Neither a cranky hamstring nor No. 25 Oklahoma was able to slow down Brandon Johnson and San Diego.
Johnson scored 18 of his 22 points in the first half, then his Toreros teammates took over to beat the Sooners 76-64 Wednesday night in the first round of the Great Alaska Shootout.
It was the second loss in five days for the Sooners (2-2), who lost to Virginia Commonwealth on Saturday night. Willie Warren led Oklahoma with 30 points, mostly after the outcome was decided.
"We're not a very good team right now," Oklahoma coach Jeff Capel said. "We had a stretch there in the first half, where we started to play with some energy and some passion,"
The Toreros (3-1), from the West Coast Conference, outrebounded Oklahoma 42-31. Chris Lewis had 10 and De'Jon Jackson had seven.
"I had no idea we could outrebound them the way we did," San Diego coach Bill Grier said.
The Toreros raced to a 12-3 lead in the first six minutes, fell behind 20-14, then scored the next 14 points to lead 28-20 with two minutes remaining. Grier credited his four seniors with not panicking when Oklahoma fought back.
Johnson kept firing, taking a few questionable shots, but finished 7 of 13.
"If I stay aggressive, I feel like my team will follow me," he said.
His 3-pointer at the buzzer gave San Diego a 33-27 lead at halftime. Oklahoma tried pounding the ball inside early in the second half and 290-pound freshman Tiny Gallon had three quick baskets in the paint.
Johnson began noticeably limping from a strained hamstring that has been slow to heal but it didn't matter. Roberto Mafra hit a step-back jumper from close range to start a 13-4 run with 18 minutes remaining and San Diego raced to a 50-35 lead.
The Toreros pushed it to 72-49 on a 3-pointer by Patrick McCollum with five minutes remaining, and there was little Oklahoma could do.
"We have not been able to get stops in the games we've played," Capel said. "It's our fourth game, and we've yet to defend at the level we need to defend at."
McCollum finished with 12 points and De'Jon Jackson had nine points for the Toreros.
The tournament is sponsored by Carrs/Safeway.