California tailback Jahvid Best slammed to the ground after a terrifying fall into the end zone and the Golden Bears never recovered from losing their star.
Sean Canfield and Oregon State were too much for stunned Cal.
Canfield threw for 342 yards and two touchdowns and ran for a score Saturday night in Oregon State's 31-14 victory over No. 23 Cal, which lost Best to a concussion in the second quarter.
The Bears (6-3, 3-3 Pac-10), who had won three straight to get back in the Top 25 for the first time following a four-week absence, tried to regroup after watching Best land on his head in the end zone following a leaping touchdown over a defender.
But they looked out of sync and lost their fifth straight at home to the Beavers. Oregon State (6-3, 4-2) became bowl eligible.
"It's a great win to beat Cal down here again," Canfield said. "I've never lost down here and it's nice to go out that way."
Best briefly lost consciousness. He was carted off the field and taken to the emergency room. He had movement in all of his extremities, something coach Jeff Tedford quickly told his players so they would know their teammate was all right.
Tedford said results of an initial exam came out normal.
"It's very sobering when that happens," Tedford said. "When it happened, it was unbelievably scary. He was out of it pretty good."
Canfield got everybody involved. He completed 29 of 39 passes with nine to Jacquizz Rodgers and six each to James Rodgers and Joe Halahuni.
It was the third straight game Cal gave up more than 300 yards in the air. Damola Adeniji had five catches for Oregon State, which leads the Pac-10 in passing.
"It was great to see so many guys contribute," Canfield said.
Lance Mitchell's 18-yard interception return early in the third quarter set up Justin Kahut's 24-yard field goal that made it 24-7. The Beavers have won three in a row against Cal and nine of the last 11.
Canfield completed 11 of his first 13 passes, including five straight to start the game. Canfield's first incompletion came in the final minute of the first quarter, but he then immediately connected with Adeniji on a 32-yarder.
Canfield threw a 15-yard TD strike to James Rodgers early in the second quarter for the Beavers, who have won four of their last five games and are in position for a school-record fourth consecutive bowl berth.
Jacquizz Rodgers was held to 67 yards rushing on 25 carries but had a late 24-yard TD run.
Cal, meanwhile, struggled to get anything going offensively-and that only became worse after Best's injury. The Bears were held to one first down and 45 yards in the first quarter, 37 of those coming on one pass play.
Best's helmet came off on impact. He vaulted into the air over Oregon State safety Cameron Collins and was at least 5 feet off the ground. Best's jersey was removed and he was wearing an oxygen mask when taken away.
"He went airborne into the end zone and I tried to tackle him," Collins said. "I believe he came down wrong. It's really unfortunate. As a team we took a knee and said a quick prayer for him. As a competitor, you never want to see something like that happen."
Best missed practice Tuesday and Wednesday with a slight concussion sustained in the team's 23-21 win at Arizona State last Saturday, but participated in full during Thursday's workout. The concussion wasn't diagnosed right away.
The latest injury-with 6:07 before halftime-silenced Memorial Stadium, where fans chanted "Jahvid! Jahvid!" before everything went quiet to see what happened with the 20-year-old junior.
"I was standing right there. You knew right when he landed it was something," Cal quarterback Kevin Riley said. "His eyes were blank and he was trying to breathe."
Best's teammates went down on their knees and waited, then moved to the end zone as trainers and doctors took him away on a stretcher. The game was delayed 13 minutes. Some of Oregon State's players who were on the field at the time huddled together in support.
Beavers coach Mike Riley kept his team on task.
"It's always an eerie thing in a game when it's so quiet and somebody gets hurt like that," Riley said. "It's just scary."
Kevin Riley, who was helped off the field just before halftime after a hard hit, was 19 of 34 for 200 yards and one touchdown, a late 3-yarder to Verran Tucker.
In Cal's last 39 home games, the Bears are 0-7 against Southern California and Oregon State and 32-0 against all other opponents.