Matt Barkley lay flat on his back in the middle of the rain-slick Rose Bowl turf.
In the final minutes of UCLA's 38-28 victory over USC on Saturday, Bruins linebacker Anthony Barr drilled USC's senior quarterback on a blitz. And for several moments, Barkley did not get up.
He finally rose to his feet and walked unassisted to the sideline, but his day was over.
And for Barkley — and the Trojans — it was a day to forget.
The Bruins turned two interceptions — including one in the first play — into touchdowns, pressured Barkley into other bad throws and eventually knocked him out of the game.
Barkley emerged from the locker room with his right arm inside his sweats, presumably protected in a sling. He would not discuss his injury.
"I would take the loss on myself," he said, "because I do every loss."
Barkley completed 20 of 38 passes for 301 yards and three touchdowns and nearly led the Trojans back from a 24-0 deficit.
But the player who guided the Trojans to three victories over the Bruins, including a 50-0 rout last season, was unable to engineer another in what will be his final appearance in the Rose Bowl stadium.
"I played up and down," he said.
Barkley had hoped to return to Pasadena on Jan. 1 to play in the Rose Bowl game for the first time, but that scenario ended as USC fell to 7-4 overall.
"There were times I felt like we could've broken the game open," he said. "But it just didn't happen."
Now, a team that began the season ranked No. 1 in several polls is looking at possibly spending New Year's Eve in places such as El Paso for the Sun Bowl.
Barkley, who gave up a chance to enter the 2012 NFL draft after last season, said he did not regret his decision to return for a final college season.
"There's nothing you can do now," he said. "Why sit and pout about it? It isn't how I expected it to turn out."
Barkley began the season as the Heisman Trophy front-runner, but he has struggled to regain his form of 2011. He has passed for 36 touchdowns but 15 of his passes have been intercepted, eight more than last season and one more than he had as a freshman in 2009.
Barkley was outplayed Saturday by Bruins redshirt freshman Brett Hundley, who completed 22 of 30 passes for 234 yards and a touchdown and also ran for two scores.
"You wouldn't think that we would lose this game with a senior quarterback versus a freshman," USC Coach Lane Kiffin said. "Usually you don't, just like a veteran versus a rookie."
Despite Saturday's horrid start, USC finally got on track and appeared positioned to possibly extend a five-game winning streak against UCLA and triumph for the 13th time in 14 games against their rival.
"When you're playing a team like USC with a quarterback like Matt Barkley, you don't ever feel like the game is in control," Coach Jim Mora said. "You never feel secure."
Barkley's touchdown passes to receiver Nelson Agholor and tight end Randall Telfer in the second quarter pulled the Trojans to within 24-14 by halftime. Defensive lineman George Uko recovered a fumble in the end zone early in the third quarter to make the score 24-20, and the Trojans appeared poised to pull off one of the greatest comebacks in the history of the series.
But USC went three and out on its possession, which ended with a blocked punt by Eric Kendricks that the Bruins converted into a touchdown and a 31-20 lead.
Kendricks picked off a Barkley pass early in the fourth quarter to seemingly end the Trojans' threat, but Barkley connected with Marqise Lee for a third touchdown and then with Robert Woods for a two-point conversion to pull the Trojans to within three points.
UCLA pushed the margin to 10 with another touchdown, giving Barkley a final chance with 3:54 left.
He drove the Trojans to the Bruins' 27-yard line before Barr burst through and nailed him.
"I got a free shot at him," Barr said, "and took my shot."
Barkley's status for next week's regular-season finale against Notre Dame is uncertain, hearkening back to 2010 when he was forced to sit out against the Fighting Irish because of an ankle injury. With backup Mitch Mustain starting, the Trojans lost at the Coliseum, ending an eight-game winning streak against the Irish.
Barkley sounded down but not defeated about the way the season has played out.
"You have to be optimistic," he said, "about how we can finish the season on a good note."