It was a wild finish to the first major of the year, and in the end Collin Morikawa etched his name into the Wanamaker Trophy. Here's how things ended up at TPC Harding Park, where Morikawa broke away from a crowded leaderboard to win the PGA Championship:

Leaderboard: Collin Morikawa (-13), Paul Casey (-11), Dustin Johnson (-11), Matthew Wolff (-10), Jason Day (-10), Bryson DeChambeau (-10), Tony Finau (-10), Scottie Scheffler (-10)

What it means: Chaos reigned for much of the afternoon at the first major in 13 months. The top of the leaderboard was a revolving door, with at one point there was a seven-way tie for the lead. But the player to break free from the logjam was Morikawa, who chipped in for birdie on No. 14 and then hit the shot of the tournament two holes later. It's his second win since the restart and third win of his burgeoning career. Just 15 months after he was playing for nearby Cal, Morikawa joins Rory McIlroy, Tiger Woods and Jack Nicklaus on a decorated list of players who won their first PGA at the age of 23.

Round of the day: Morikawa started the day two shots off the lead, but he quickly made a move with two early birdies. His sizzling back-nine 31 included an eagle on No. 16 and added up to a 6-under 64, as Morikawa went bogey-free over his final 22 holes while playing that stretch in 9 under. The 64 not only got him the win, but it matched the low round of the week.

Best of the rest: Wolff made the biggest charge of the early finishers, carding a 5-under 65 to take the clubhouse lead at 10 under. A college peer of Morikawa's just last year, he capped a torrid stretch from Nos. 7-10 with an eagle on the par-5 10th to play those holes in 5 under. He closed with two birdies over his final three holes to grab a high finish in his first career major start.

Biggest disappointment: The reign of Brooks Koepka ended not with a bang, but a whimper. After talking up his chances after the third round as he sought a third straight PGA title, Koepka dropped from contention with a 4-over 39 on the front nine. Koepka didn't make a birdie until No. 12, and a 4-over 74 dropped him from two shots off the lead into a tie for 29th, 10 shots behind Morikawa.

Shot of the day: Morikawa took the lead with a chip-in on No. 14, but he sealed it with his tee shot on No. 16. Tied with Casey at the top, he hit a 294-yard drive that bounded onto the green and nestled 7 feet away from the hole, setting up a decisive eagle.