Happy Opening Day! As the 2021 MLB season officially began, we tracked the key takeaways and signature moments from each game across the country.

Beginning with a snow-filled AL Central matchup in Detroit and a Hyun-Jin Ryu vs. Gerrit Cole pitching showdown in New York, there was plenty to talk about right from the start of the new season.

It didn't all go smoothly as baseball returned to a full 162-game schedule from a pandemic-shortened 2020 season, though, as the Boston Red Sox's home opener against the Baltimore Orioles was postponed due to rain and the Washington Nationals-New York Mets matchup in D.C. was postponed due to COVID-19 issues.

Here are the only-in-baseball moments, must-see plays and overarching themes that caught our eye on the first day of the 2021 season.

Colorado Rockies 8, Los Angeles Dodgers 5

When a two-run homer isn't a two-run homer

Baseball is a glorious, comical game that tests the deepest reaches of rationality. Take, for example, the season opener between the defending World Series champion Los Angeles Dodgers and the Colorado Rockies, who are, in just about every way, the anti-Dodgers.

The micro example of this arrived in the third inning, when Dodgers center fielder Cody Bellinger launched a ball to left field that caromed off Raimel Tapia's glove and over the fence at Coors Field. Bellinger, trotting to celebrate his feat, did not realize that teammate Justin Turner had retreated toward first, fearing the ball had been caught. They crossed on the basepaths. Bellinger was called out. Turner scored. Bellinger was credited with an RBI single. That went over the fence. Which ... is not rational.

Here's the macro event: The Rockies won. The Rockies, who not only traded their best player this winter, but included $51 million to offset his salary as a parting gift. The Rockies, whose organizational foibles have become the standard by which other teams judge their screw-ups. The Rockies, who are not good.

And that's baseball. That's the glory and why a genuinely bad team can face a genuinely great one and beat it -- in this case by the score of 7-4 -- and nobody bats an eye or panics or thinks twice about it.

It's entirely irrational that one group of men can be that much better than another at something and when that superior group loses to the inferior one it's just another shrug emoji. It's genuinely comical that Chris Owings, who had 11 hits all of last season and hadn't tripled in nearly two years, whacked three hits, including a triple, and was the best player on the field.

None of it makes sense, and that's why baseball is so easy to love. There is no chalk. There is no guarantee. There are the Dodgers, who expect to win 100, and there are the Rockies, trying not to lose 100, and the latter beat the former in the first game of the season. Because of course they did. -- Jeff Passan

Toronto Blue Jays 3, New York Yankees 2 (10 innings)

Don't sleep on Teoscar Hernandez

The Blue Jays project as one of the most exciting young teams in the sport. While a lot of the hype surrounds the trio of big league sons in Bo Bichette, Vladimir Guerrero Jr and Cavan Biggio, one of the team's biggest X-factors this season will be Teoscar Hernandez, who put together a breakout campaign in 2020, hitting .289/.340/.579 with 16 homers and 34 RBIs in 50 games.

Hernandez changed the day for the Blue Jays when he hit a massive, 437-foot solo home run on a 86 mph slider from Yankees ace Gerrit Cole to tie the score at 2 in the sixth inning, while slotting in as the team's cleanup hitter between Bichette and Guerrero.

The 28-year-old outfielder's bat will be crucial for this Toronto team if it hopes to make the playoffs. His three-hit performance in a 10-inning win was a promising start. -- Joon Lee

Gary Sanchez gives Yankees fans a reason to cheer

At least for one game, Gary Sanchez managed to keep his critics at bay.

Yankees fans maintain a mercurial relationship with Sanchez, but the catcher started off the 2021 season strong by blasting a two-run, 407-foot home run to left field off Blue Jays ace Hyun-Jin Ryu in his first at-bat of the year.

Whether or not Sanchez can remain the starting catcher for the Yankees will be one of the team's most prominent storylines in the early part of the season. The backstop hit .147/.253/.365 in 49 games in 2020 and the team benched him during the playoffs, raising the question of whether the 28-year-old two-time All-Star is still the team's best long-term option behind the plate. -- Lee

Detroit Tigers 3, Cleveland Indians 2

Miguel Cabrera swings (and slides) through the snow

As if we needed to be reminded that anything can happen at any time in baseball, a stark refresher of that truism was gifted to us on a snowy day in Detroit, early in one of the first games of the 2021 MLB season.

On the mound was Cleveland righthander Shane Bieber, who dominated his way through the short 2020 season, going 8-1 with a 1.63 ERA en route to his first AL Cy Young Award. At the plate was future Hall of Famer Miguel Cabrera, the face of the Tigers, who has battled age and injury in recent seasons as he pursues historic milestones for a rebuilding franchise.

Accentuating that frozen moment -- the pun is intended -- was a snowfall at Comerica Park so thick that you couldn't tell at first that what was about to happen actually did happen.

With two outs and Jeimer Candelario at first base, Bieber threw a fastball in the upper outside quadrant of the strike zone. Cabrera lashed at it, sending a drive to right field. On the broadcast, it was impossible to tell what was the ball and what was snow, but the ball just cleared the railing in right field.

Not realizing that he had indeed just hit career home run No. 488, Cabrera -- and though the game was played on April 1, this was no April Fools' joke -- slid into second base. -- Bradford Doolittle

Philadelphia Phillies 3, Atlanta Braves 2 (10 innings)

Last season, the Phillies' bullpen had a rough go of it. Really rough. Like whatever the grittiest grit score is for a sheet of sandpaper, the Phillies' bullpen grit score was rougher than that. Philly's 7.11 bullpen ERA in 2020 was the worst of any team in 91 years. Well, it's a new season, and that bullpen was the talk of their camp in Florida, and for happy reasons.

By the seventh inning of the Phils' opener Thursday against Atlanta, ace Aaron Nola was rolling through the vaunted Braves' lineup and nursing a 2-0 advantage. He held the Braves to no runs on just four hits without walking a batter. He retired the first two batters in the frame, but then rookie Cristian Pache doubled. Nola, one of baseball's true and rare innings-eaters, had thrown just 81 pitches.

The 2020 version of Phillies manager Joe Girardi would have had an easy choice: Stick with his ace or turn it over to the worst bullpen since the Herbert Hoover administration? Nola would stay in. Easy call. The 2021 version of Girardi made the same choice, and while it was probably the right one, even on a day when Nola was the only starter during the day contests to record an out in the seventh inning or later, it didn't work out.

The Braves sent up veteran pinch hitter Pablo Sandoval, and the Panda turned on an inside fastball and blistered it at 111.7 mph, per Statcast, sending it into the right-field seats for a tying homer. And just like that, Nola's heretofore dominant day was done.

But that's where Girardi's story brightened, and perhaps might make him cringe just a little less in games to come when he turns to his relief staff. Archie Bradley, Jose Alvarado, Hector Neris and Conner Brogdon combined to throw 3⅓ scoreless innings without too much drama. The game eventually reached extra innings, where the Phillies won on Jean Segura's single.

Just one game. But it might have been just the kind of game the Phillies needed to start their season.

You've got to see Bryce Harper's cleats for yourself

Bryce Harper has the best cleats on #OpeningDay pic.twitter.com/r8UzRZYt8Q

— Cut4 (@Cut4) April 1, 2021

Bryce Harper upped the stakes with his ongoing Phillie Phanatic fetish before the season opener against Atlanta by sporting some wild, Phanatic-inspired cleats with crazy eyes and a stuffed toy affixed to them. These were even more bold than the version Harper sported last July, which were just kind of fuzzy. Harper has even swung a bat featuring the Phanatic's face. Could the final iteration be Harper playing in the actual Phanatic costume? -- Doolittle

Milwaukee Brewers 6, Minnesota Twins 5 (10 innings)

The meeting between contenders in their respective Central divisions was an excellent Opening Day affair. Big-time pitching. Costly errors. A ninth-inning comeback. Extra innings. Josh Hader looking better than ever. Walk-off win for Milwaukee.

Amid it all was Twins center fielder Byron Buxton, 27 years old, still beyond gifted, still prone to doing amazing things, like hitting a baseball to the farthest reaches of American Family Field, 456 feet to left-center field, in the sort of moment that makes Opening Day feel like the beginning of something.

Nobody in baseball teases and tantalizes like Buxton, the one-time top prospect in baseball whose dueling injuries and ineffectiveness get downplayed by his sheer talent on days like Thursday. The Twins, even without Josh Donaldson, who tweaked a hamstring running the bases in his first at-bat, are a good team. The Twins, with Buxton doing the sort of things he did in Game 1, genuinely scare the Chicago White Sox.

It wasn't just the home run. Buxton walked twice. He stole a base. He patrolled center field with the range and accuracy of a well-calibrated drone. The threat of his arm prompted runners to hold at bases. It was the quintessential Buxton showing: the bat, the legs, the glove, the arm.

Yes, it's one game. Buxton has done this before. Last year, he hit 13 home runs in 39 games ... and walked twice. For him to match his entire-season total in one game was a pleasant surprise, though it's one that registers second on his list of achievements for the day. That home run -- the longest of his career -- was possibility personified. Opening Day is the day for dreamers, and there is perhaps no one better in baseball to dream on than Byron Buxton. -- Jeff Passan

Pittsburgh Pirates 5, Chicago Cubs 3

Ke'Bryan Hayes looks like the real deal

Pirates rookie phenom Ke'Bryan Hayes picked up where he left off in spring training, where he hit .431. On Thursday, he took Kyle Hendricks deep in his first at-bat in the first inning, once again showing the baseball world why he's a favorite to win Rookie of the Year in the NL.

In just 24 games during the shortened 2020 season, Hayes gave us a taste of what he could be: a dynamic offensive and defensive player, and nothing seen so far has changed that perception. Hayes added a walk later, but his two-run home run in the first inning was the difference in the Pirates' win over the Cubs. Hayes looks like the real deal. -- Jesse Rogers

St. Louis Cardinals 11, Cincinnati Reds 6

The Reds' grand experiment of deploying third basemen at shortstop and second base got off to a rocky start when the Cardinals scored two runs on a Eugenio Suarez error.

It didn't help that the Cardinals were in the midst of knocking around Reds ace Luis Castillo for six first-inning runs. And it certainly didn't help that it was Suarez's first fielding chance during a real game since his much-scrutinized, late-spring move from the hot corner to shortstop.

On the play in question, the Cardinals had a run in, the bases loaded, and one out. Yadier Molina chopped one to Suarez, who had to move a couple of steps to backhand the ball. With the slow-footed Molina running, a rally-killing double play might have been on Suarez's mind. Instead, as he tried to make a quick transfer from glove to throwing hand, Suarez lost his grip on the ball, which fluttered out to left field as two runs scored.

Shortly thereafter, St. Louis' Dylan Carlson cranked a three-run homer off the right-field foul pole and the Cardinals were on their way to the six-spot. Suarez also committed an error on his second chance, when he backhanded a grounder from Paul Goldschmidt and buried a throw that skipped past first baseman Joey Votto in the second inning.

The Reds battled over the rest of the game, but a six-run gap is hard to close. Suarez converted his last three fielding chances to end up with a fielding percentage of .600 for the game. He also hit a home run, but the lingering question remains: How long can the Reds stick with this experiment? -- Bradford Doolittle

Tampa Bay Rays 1, Miami Marlins 0

In years past, Tyler Glasnow faced competition from Blake Snell and Charlie Morton for the best pitcher in the Rays' rotation. No longer. Glasnow cemented himself at the top of the Tampa Bay rotation. While Glasnow was ranked 39th in ESPN's MLB Top 100, his Opening Day start Thursday showed that the number might've been too low.

Capital L pic.twitter.com/s7daJdkKPV

— Tampa Bay Rays (@RaysBaseball) April 1, 2021

Glasnow, 27, went six innings against the Marlins, allowing no runs and one hit while striking out six with no walks. Glasnow added a slider this offseason that he put on full showcase, accounting for 26 of his pitches. Paired with his electric 100 mph fastball, the new breaking pitch gives the Rays' righty an extra tool to keep hitters off balance.

"I think the last couple starts in spring, I've kind of opened up my eyes to like, 'Wow, I've been really kind of getting by on two pitches when I really should have not been," Glasnow told reporters this week. "I just think it makes it so much easier for me in terms of options and guys aren't selling out." -- Lee

San Diego Padres 8, Arizona Diamondbacks 7

Padres pen cleans up for Yu Darvish

The Padres hadn't officially announced a closer, but Mark Melancon finished off the 8-7 victory with Emilio Pagan pitching the seventh and Drew Pomeranz the eighth, so take note, fantasy owners.

There have been some concerns about the San Diego bullpen, especially with a few projected key relievers on the injured list, but the Padres stockpiled plenty of good arms. Add in Keone Kela tossing a scoreless sixth inning, and the final four relievers combined to allow two hits over the final four scoreless frames.

Of bigger concern was the performance of both starting pitchers. Yu Darvish was given the Opening Day start for his Padres debut and couldn't get through five innings even though he entered the inning with a 6-1 lead. He was visibly and understandably frustrated that he couldn't get that third out of the fifth. Given the health issues of Dinelson Lamet (elbow) and Blake Snell's questionable durability history, the Padres need a big season from Darvish. It took him more than a year before he settled in with the Cubs, but the Padres are counting on him to be their ace -- from the get-go.

As for the Diamondbacks, Madison Bumgarner did nothing to assuage concerns about his future, after he went 1-4 with a 6.48 ERA in 2020. He allowed six runs and seven hits, including home runs to Eric Hosmer and Wil Myers, in four innings. After averaging 88 mph on his fastball last year, at least he averaged 90.2 Thursday, so maybe that's a positive, but with three walks the command wasn't there and both home runs came off flat cutters. -- Dave Schoenfield

Kansas City Royals 14, Texas Rangers 10

The Royals won a long, messy game over the Rangers at home that required them to overcome a five-run Texas first, which they erased in the bottom of the first, then another three-run deficit a couple of innings later.

The first inning was historic, if not aesthetic, as Elias reported that it was the first time in an Opening Day contest in which both teams scored at least five first-inning runs.

The slog continued for four hours and 26 minutes and featured 17 walks, three errors (all by the Rangers), a wild pitch, two passed balls, three hit batters and a hitter (Jorge Soler) who reached on catcher's interference. Yet, for Kansas City, it was a beautiful lid-lifter in its own way.

The Royals were refreshingly aggressive during the offseason, with KC's Opening Day lineup featuring four position players making their debuts for the team. They all contributed to the win:

• Andrew Benintendi overcame a first-inning gaffe in which he allowed three runs to score by diving and whiffing on a sinking liner off the bat of Texas' Nate Lowe. Benintendi made a fine play on a foul pop shortly after that and ended up reaching base a couple of times and scoring two runs.

• Carlos Santana did exactly what the Royals acquired him to do. He walked three times, worked at-bats of epic lengths, singled and scored two runs.

• Michael A. Taylor homered, singled twice and drove in three runs. He also threw out two baserunners from center field, both on throws that Statcast registered at over 95 mph. Royals center fielders had only one assist all of last season.

• Rookie Kyle Isbel singled three times and drove in two. He also had a couple of chances to showcase the speed on the basepaths that made him a fairly surprising addition to the Royals' roster.

With the win, the Royals accomplished something they had not done in almost exactly two years. They finished a game with a record over .500. It's a start. -- Doolittle

Houston Astros 8, Oakland Athletics 1

Yes, there were boos from the crowd of 10,000 or so in Oakland, with the loudest ones directed at Astros third baseman Alex Bregman. Zack Greinke did a lot to silence the A's fans, however, and then Bregman himself delivered a final message that perhaps suggests the Astros will put their offensive woes of 2020 behind them.

Opening Day hasn't been kind to Greinke. He allowed three home runs and seven runs in 2017 and four home runs and seven runs in 2019, and was 0-2 in four career openers. He was brilliant in this game, however, with six scoreless innings -- even though only three of his 82 pitches reached 90 mph. In this era when velocity is everything, Greinke continues to be one of the most enjoyable pitchers in the game, as he hit just about every radar gun reading from 69 to 91. Watch and learn, kids.

As for Bregman, like several other Astros hitters, he struggled in 2020 in the wake of the cheating scandal. His OPS dropped from 1.015 to .801 (although he particularly struggled after a return from an IL stint). He doubled, and his home run in the eighth was a 418-foot blast to left. (OK, he was still booed as he rounded the bases.) Another good sign for Houston: Yordan Alvarez, back after missing all but two games in 2020 due to surgery on both knees, hit a two-run, opposite-field double off the wall. -- Schoenfield

Los Angeles Angels 4, Chicago White Sox 3

Angels manager Joe Maddon, who has spent the past two years actively railing against the way advanced analytics have seemingly stripped away some of the game's emotion, has expressed a desire for his team to play "1985" baseball.

Opening Day provided a snapshot.

The Angels' offense manufactured runs in an old-school fashion against Lucas Giolito and an electric White Sox bullpen, most notably with two-out walks by Mike Trout and Anthony Rendon in the fourth and an 11-pitch plate appearance that led to a critical walk by Justin Upton in the eighth. The pitching held up, first with Dylan Bundy hanging tough through six innings and then with three relievers retiring nine of 10 batters. And the defense was on point, highlighted by a spectacular diving play in the hole from shortstop Jose Iglesias.

The Angels struck out 10 times, but only four times over the final six innings. They got some encouraging production from Upton and Max Stassi -- not to mention a 107 mph line drive from Shohei Ohtani -- but they also worked counts, moved runners over, didn't let the game slip away early and locked it down late.

It was a recipe for the way Maddon believes they can win the American League West.

"I loved it," he said. "Didn't you love it?" -- Alden Gonzalez

Seattle Mariners 8, San Francisco Giants 7

The Giants played seven great innings of baseball. Unfortunately, they also played the bottom of the eighth inning. And the bottom of the 10th.

San Francisco led 6-1 with six outs to go. Kevin Gausman had throttled the Mariners for 6 2/3 innings. Buster Posey homered in his first at-bat since 2019. The game was in the bank. Instead, the Mariners became the first team since the 2002 Expos to win their opener while trailing by at least five runs in the eighth inning or later. They scored six runs on just three hits in the eighth as Giants relievers walked three batters and hit another. Then, Brandon Belt turned a potential inning-ending double play into a two-run throwing error.

Seattle led 7-6, but the game wasn't over yet. Alex Dickerson tied it for the Giants with a home run in the top of the ninth. In the 10th, Jose Alvarez came on for San Francisco and walked all three batters he faced. With the runner-on-second rule, that meant the Mariners, well, walked it off. It was the fourth extra-inning game of the day, tying a record for Opening Day. We also had eight one-run games -- two more than any other first day in MLB history.

That won't provide any solace to Giants fans, who saw all the beauty (four home runs!) and all the pain (nine walks!) baseball loves to serve up. -- Schoenfield