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.