ESPN Men's Basketball

LOS ANGELES -- After four years spent patiently rebuilding Oregon State's program from its foundations, coach Craig Robinson is two wins away from forcing President Barack Obama to predict his brother-in-law's fortunes in his NCAA tournament bracket.

Robinson's Beavers finally made their breakthrough Thursday, surviving missed free throws, blown leads and a spine-chilling finish to outlast top-seeded Washington in the Pac-12 tournament quarterfinals.

Jared Cunningham hit a go-ahead layup with 31.8 seconds left, and ninth-seeded Oregon State blew a 15-point lead in the second half before rallying for an 86-84 victory over the two-time defending tournament champion Huskies. The Beavers will play fourth seed Arizona in the semifinals on Friday.

"We have a very emotional team for a lot of reasons," Robinson said after fighting to contain the Beavers' locker-room glee with another tournament game looming in 24 hours. "But I know that I could not be more proud of a team, and have not been prouder of a team, than I am of this team. We have fought hard and lost our share of games by five points and under, and it's not due to these guys' lack of hard work."

Indeed, the Beavers needed hard work to win two conference tournament games for the first time in school history, but they also needed a little luck.

Cunningham scored 18 points and hit two free throws with 6.2 seconds to play despite missing five additional free throws in the final 31.8 seconds. Devon Collier had 19 points and seven rebounds for the Beavers (19-13), who outlasted the league regular-season champion Huskies only because Tony Wroten, Washington's freshman star, couldn't hit four late free throws of his own.

"That stretch at the end was nail-biting," said Cunningham, the Pac-12 scoring leader entering the tournament. "We've been together from the start. We're a close-knit group, and we just love each other and want each other to do well."

Oregon State's 48-33 lead in the second half turned into an eight-point deficit in less than 11 minutes. Washington then blew a six-point lead in the final 2½ minutes despite Cunningham's misses at the free-throw line.

Cunningham missed his final two tries with 2.3 seconds left, but the rebound went out of bounds off a Washington player. Oregon State ran out the clock on an upset that should get the attention of the commander in chief.

"It was a rocky time," said Oregon State forward Joe Burton, who scored 14 points and hit a key layup with 1:47 left. "Even at half, Coach said they were going to make a run."

Wroten had a career-high 29 points in the highest-scoring performance by a Washington freshman, but the Pac-12's top rookie clanked two free throws with 18.3 seconds left and two more with 8.7 seconds to play.

Wroten didn't want to talk about it afterward in the Huskies' somber locker room, politely ignoring questions while scrolling through messages on his phone.

"Tony is feeling really down right now, but he's a great player and he has a short memory," said C.J. Wilcox, who scored 16 points. "He played excellent for his first tournament."

Terrence Ross scored 15 points for the Huskies (21-10), who might be consigned to the NIT after this upset loss as the top team in a league widely perceived as weak. Washington had won 16 of 20 to claim the Pac-12 title, but the Huskies realize they could be in trouble on Selection Sunday.

"We certainly didn't help ourselves today, but I would think we could find ourselves in (the NCAA tournament)," Washington coach Lorenzo Romar said.

Washington made a 22-3 run after falling behind 48-33 in the opening minute of the second half, but Oregon State finished on a 13-5 run. The Huskies could blame the loss squarely on free-throw shooting after going just 9 for 21 in the second half.

"We talked about how important the little things are," Romar said. "If we have an opportunity to play again, that's something we've got to make sure we focus on."

Cunningham managed just four points in the Beavers' tournament-opening win over Washington State on Wednesday, and he missed his first three shots against the Huskies, including an easy alley-oop layup on a fast break. The Oakland product eventually got going as the Beavers outworked the cold-shooting Huskies throughout the first half.

Ahmad Starks finished with four 3-pointers and 14 points for Oregon State, which made a 21-7 run late in the first half. Burton's tip-in with 5.5 seconds left sent the Beavers into halftime with a 13-point lead, earning a standing ovation from their small but boisterous group of fans including former NBA stars Gary Payton and A.C. Green.

Washington got rolling with a boost from Abdul Gaddy, who scored eight of his 13 points in a three-minute span while the Huskies took charge. Starks hit his fourth 3-pointer with 59 seconds left to trim Washington's lead to 83-82, and Cunningham put Oregon State ahead moments later.