BERKELEY, Calif. (AP) - Freshman Keenan Allen celebrated his second touchdown by slapping a high-five with someone in the stands. That earned California a celebration penalty.
He quickly apologized to coach Jeff Tedford for the mistake. Aside from that tiny hiccup, Allen was otherwise brilliant in his collegiate debut.
Allen ran 18 yards for a second-quarter touchdown, then caught a 48-yard TD pass from Kevin Riley to start Cal's second-half scoring in a 52-3 rout of UC Davis on Saturday. Allen made four receptions for 120 yards.
"I just came out here and played my game and all things went well. I was real nervous but I tried to get the guys to keep me calm," he said. "I've been waiting for this day for a long time. I got caught up in the moment (on the penalty). I didn't know we couldn't do that until after the play."
Riley threw for 258 yards and three touchdowns in just more than a half of work, helping Tedford become California's winningest coach in the modern era as the Golden Bears won for a sixth time in their last seven season openers.
Tedford talked to Allen about his celebration and believes he got the message across.
"He made some big plays today. He can do almost anything, I think. He's a great athlete," Tedford said. "I would assume he's going to be able to compete on any stage. He's kind of unflappable. I don't think he's caught up on the big stage at all. He has a lot of confidence in his ability but he's very low key about it."
Shane Vereen ran for two scores and caught a touchdown pass, all in the first half. Marvin Jones made a 13-yard TD reception for Cal, which jumped out to a big lead early to avoid becoming an upset victim by the Aggies, the way Stanford did five years ago during Davis' last visit to a Pac-10 school.
Riley, a senior, completed his first nine passes and 14 of 20 overall _ including Jones' career-best 51-yard reception on which he made the play despite pass interference that was declined.
As excited as everybody is about Allen's potential, it gets a lot harder from here. Colorado comes to town next Saturday.
"He's going to make plays but you've got to think we're going to be playing better competition and it's not going to be as easy," Riley said. "You can tell he's a football player. We had good moments and bad moments. We'd like to be more consistent on some things."
Still, Cal came out and played a heads-up game against a lower-tier opponent. Tedford thought his team was tight during Friday's practice.
"He's going to be pretty amazing," Vereen said of Allen.
UC Davis avoided being shut out when it got a 43-yard field goal from Sean Kelley at the 10:24 mark of the third quarter. Not much went right for the Aggies, who shocked Stanford 20-17 on The Farm in 2005.
Moments after a timeout on Cal's opening series of the game, Riley fumbled the snap and Davis' Bobby Erskine recovered. That gave the Aggies first-and-10 at the Bears' 43, but they went three and out.
Cal capitalized on its next drive, when Riley hit a wide-open Vereen on a 23-yard scoring pass in the right corner of the end zone with 4:11 left in the first quarter to make it 7-0. Isi Sofele ran for a nifty 17-yard gain on the previous play to put Cal in good position.
Riley's day was done early in the third quarter, as he gave way to backup Beau Sweeney.
UC Davis redshirt freshman quarterback Randy Wright completed 8 of 22 passes for 57 yards in his first career start. He became the first freshman to start an opener for the Aggies since Ryan Flanigan in 2000.
Wright completed a 14-yard pass to Dean Rogers on the Aggies' first play from scrimmage and completed his second attempt before missing on third down under blitzing pressure. After that first completion, reigning Great West Conference champion UC Davis managed just 17 more yards and didn't have another first down in the first half.
"It was their speed and size _ we can't duplicate that in practice," Wright said. "It was frustrating at times."
The Aggies are in their fourth season in Division I. They played without senior Joe Trombetta, the team's leading returning rusher and second-most productive receiver in 2009, because of a hamstring injury sustained during camp. The Aggies held him out as a precaution and hope he will return next week when they host Portland State.
Cal is seventh in the preseason Pac-10 media poll and begins the year unranked for only the fourth time in Tedford's nine seasons. The Bears are 6-0 in openers at home under Tedford.
Tedford passed Pappy Waldorf for the most coaching victories at Cal in the modern era with 68. Waldorf went 67-32-4 from 1947-56.
"You hear so many stories about Pappy Waldorf and Pappy's boys and the tradition they set for Cal football," Tedford said. "It's a lot of hard work by everyone. It's an honor, it really is, because of the company you keep there."
Davis is 2-18 overall against current Pac-10 teams, including a win against Arizona in 1923.
This marked the teams' first meeting since 1939. They played every year from 1932-39, all in Berkeley. Cal is 9-0 in the series.
"I've been in games where I've been disappointed about how we played, but it wasn't one of those kind of games," Davis coach Bob Biggs said. "They were better."