Coach Lorenzo Romar's Huskies weren't prepared for the Pac-12 tourney opener. / Drew Sellers, Sportspress Northwest

A strong run in the second half of the regular season seemed to signal that Washington worked through its problems of youth and inexperience.

Nope.

The young Huskies crashed Thursday, early and late, falling to Oregon State 86-84 in a quarterfinal defeat that ran them out of the Pac-12 Conference tourney and perhaps the NCAA tourney.

Flat in the first half and weak in the final two minutes, the regular-season champion became the tourney’s first No. 1 seed to be ousted so early. The Beavers, little steadier, nevertheless had enough wit to prevail. But the wildly uneven mess cast even more doubt upon the Pac-12′s ability to get an at-large team to accompany the tourney champion to the big, 68-team dance that begins next week.

While mistakes abounded from coaches to players, what most will remember is that Tony Wroten, despite a career-high 29 points, blew four free throws in a row in the final 18 seconds. The killer was that Wroten, a 57 percenter during the season, made 9 of his first 11 from the line.

“I’m not sure the moment wasn’t too big for him,” Washington assistant coach Jim Shaw told KJR radio. Working through the double negative, Shaw meant Wroten, the Pac-12 freshman of the year, choked. It will be neither the first nor last time it happens to him or any player in a clutch situation. It’s plain human nature, but Wroten has always taken pride in his play during big moments.

“It looked as if (the Beavers) wanted to foul him,” Shaw said,  “to put him at the line and take it from there.”

Wroten didn’t answer questions in the locker room afterward, but deeds spoke louder — from every corner. Wroten hit 9 of 15 free throws, but reliables such as Terrence Ross (16 points) and C.J. Wilcox (15 points) also missed key freebies. Washington missed 14 of 26 from the line. OSU was little better, 17 of 32, but it was enough in a game in which each team made 32 field goals in 64 attempts.

OSU’s 50 percent shooting was the bigger part of the story. Washington’s defense was so poor in the first half that the Beavers piled up a 46-33 lead from getting open perimeter shots and pass-throughs into the paint that piled up fouls on Aziz N’Diaye, who sat out most of the second half with four fouls.

“Defensively, we just walked around and had no urgency,” said Wilcox. “I can’t really tell you why.”

That was the puzzler, how a team that knew it could clinch at least an at-large NCAA bid with a win, could come out on its heels after five days rest.

They flew home Thursday to await the NCAA selection committee’s decision Sunday on whether the 21-10 Huskies, who lost their last two games (including UCLA Saturday) after having won 10 of the previous 12 in a mediocre league, are NCAA-worthy. If they do get in, it could be as one of four teams in Dayton, OH., in a play-in first round.

“It comes but down to a certain level of toughness mentally and physically,” said Shaw. “I thought physically we were tough, but the free throws . . . mentally, we weren’t very strong.”

The Huskies seemed in control with a 77-71 lead, but Oregon State’s Jared Cunningham (18 points, 10 rebvounds, eight assists), scored nine of OSU’s final 15 points, including two from the line with 6.2 seconds to play, to advance to the semifinals Friday. The Beavers beat Washington State Thursday.

Before the typically sparse crowd at Staples Center, the Huskies had no energy for the noon start, making 10 turnovers and falling behind 48-33 early in the second half, then digging in on defense to spark a 31-10 run that seemed to rescue the game. But the Beavers outscored Washington 13-5 over the final 2:30.

In the final 32 seconds, the teams combined to miss 10 free throws, five each. It’s the kind of play that even the National Invitation Tournament might be compelled to ignore.

PAC-12 TOURNAMENT

The Pac-12 tournament determines the league’s automatic bid to the NCAA Tournament. Results so far, plus the remaining schedule:

Wednesday

Thursday

Friday

Saturday