LOS ANGELES -- The grand opening of the Lincoln Riley era at USC began with a new logo on his familiar visor and plenty of fireworks on the field from new and old faces alike.

USC scored its most points in a game since 2008 thanks to a clinical debut by quarterback Caleb Williams and three interceptions returned for touchdowns by the defense as the Trojans trounced Rice 66-14 on Saturday in the season opener.

"We understand this is just the beginning and there's so much left, so much better to play, so much better to coach," Riley said. "It's a great start; it's not anything more than that, not anything less than that."

Even if Riley didn't want to inflate the result, the game couldn't have gone much better for him. USC finished with 538 total yards, 27 first downs and a single punt that came with 12:21 left in the fourth quarter just after Williams and a host of other starters on offense had exited.

"I think we have a lot of confidence," said Williams, who transferred from Oklahoma after Riley was hired. "And we didn't just build that confidence coming out here being excited for the first game."

Williams' debut brought the most anticipation of any new Trojan heading into the opener, but it was difficult to see any semblance of pressure or expectations affecting him. He was comfortable in a pocket that allowed him to take his time and complete 19 of his 22 pass attempts (best for a USC quarterback since Matt Barkley in 2012), including throws to 12 different receivers and two touchdowns to the other highly touted transfer the Trojans snagged this offseason: Biletnikoff winner Jordan Addison.

"Since he got here, it was almost as if we've been throwing to each other for the past year," Williams said. "It's been easy."

Everything seemed easy for Williams, including using his scrambling ability to dance through the Rice defense to the tune of 68 rushing yards on six carries. It appeared as if Williams barely broke a sweat through three quarters, and when he sensed it would be time for Riley to pull him out of the game, he tried his best to keep playing.

"Oh, I didn't want to come out, so I was trying to play as smart as possible by going down before anyone could hit me," Williams said. "[Riley] said, 'I know you're trying to stay in the game.'"

"It's not Year 1 anymore," Riley joked in the media room.

For all of the attention on USC's high-powered offense, the surprise of the game was its defense. The unit came into the season with the most questions surrounding its depth and talent, and though it began the game by allowing two long drives for touchdowns, it woke up in a big way with four interceptions -- the Trojans had four all of last season -- including three returned for TDs by sophomore Calen Bullock, Alabama transfer linebacker Shane Lee and senior linebacker Ralen Goforth.

"It got real today," defensive coordinator Alex Grinch said. "You can only do so much in practice, and it's critical. No one will talk about practice more than me. But ultimately, you got to go out there on the stage."

Addison and Williams were the headliners, but plenty of other transfers and even some incoming freshmen made an immediate impact. Austin Jones from Stanford had two rushing touchdowns while true freshman Raleek Brown had eight electric touches that bode well for the Trojans' depth at the position.

For at least one game against an inferior opponent, USC didn't look like a team that had been overhauled in the offseason with more than 40 new players. Instead, the Trojans proceeded to put it all together and score more points than they had in any game under former head coach Clay Helton.

"This is definitely a statement, that's what we wanted to do," Addison said. "We had to show everybody that this wasn't just no hype. We ready to play."

The significance of the long-awaited journey to the first game under the new regime wasn't lost on Riley or any of the players. As temperatures reached nearly 100 degrees, USC announced just over 60,000 fans at Los Angeles Memorial Coliseum, where capacity is 78,647.

"We understand that in this city, and I think it's fair, we gotta go prove who we are as a team," Riley said. "We're going to do everything we can as a team to keep working so that people can't even stand the thought of not coming to a USC football game."

Added Oklahoma transfer wide receiver Mario Williams: "This is a new era, this SC."