Steve Alford reflected his team's fortunes with his every move in the final minutes.
Thomas Welsh missed a jump shot that could have tied the score for UCLA and Alford loosened the knot on his tie as he crouched along the sideline.
Jaylen Hands badly misfired on a three-pointer and Alford stood with his hands on his hips.
Aaron Holiday reached in to foul Oregon State's Drew Eubanks on a dunk and Alford turned and walked back toward his team's bench in resignation.
The UCLA coach could only go through the motions like his team toward the end of a 69-63 loss at Gill Coliseum on Thursday night that gave the Bruins a two-game losing streak and raised more questions about their ability to compete in the Pac-12 Conference.
UCLA followed its worst offensive performance of the season with another clunker. The Bruins made only 37.9% of their shots overall and were seven for 23 from beyond the arc. They were also manhandled inside, giving up 18 offensive rebounds and getting outscored, 33-22, in the paint.
The Bruins, 13-6 overall and 4-3 in the Pac-12, also failed to exhibit poise while being outscored 10-3 after Holiday's two free throws had given them a 60-59 lead with 3:24 to play. Oregon State's Tres Tinkle and Stephen Thompson Jr. made back-to-back three-pointers and UCLA couldn't recover.
"We gambled and didn't get the steal and they get a wide-open shot," said Alford, whose team has matched its conference loss total from last season only seven games into Pac-12 play. "And then instead of chasing like we had all night, we shot the gap and Stevie Thompson gets a wide-open three."
Holiday finished with 22 points but made only four of 10 shots and Welsh scored 10 points on four-for-13 shooting to go with 13 rebounds. No other UCLA player reached double figures.
"It took us a while to get it going in-out," Alford said. "I thought once we did that I thought we got good shots, we just didn't make many of them. That's stuff we've just got to shake off and show some toughness and we'll get the next one."
Tinkle scored 16 points and was one of five players to reach double figures for the Beavers (11-7, 3-3).
UCLA used full-court pressure to help force three consecutive turnovers midway through the second half, turning what had been an eight-point deficit into a 48-48 tie on a layup by Alex Olesinski. Bruins guard Chris Smith then gave his team a 54-53 lead on a driving layup, setting up a back-and-forth battle over the final minutes.
"I think they just wanted it more down the stretch," Welsh said. "They got some really good looks and they knocked them both down and in situations like that, defense is what's going to win the game. We had a one-point lead and we gave them two really good looks from three. It's hard to come back from that, especially on the road."
The game's opening minutes felt like a replay of UCLA's offensive struggles during its loss to Colorado. The Bruins missed their first six shots, five of them three-pointers, before Welsh rebounded his own miss and sank a mid-range jumper.
UCLA looked lifeless in the early going, failing to get off a shot on one possession as someone could be heard yelling "Shoot it!" from the Bruins' bench on the other end of the court.
Oregon State failed to build much of a lead because it was equally cold against UCLA's man-to-man defense. The Beavers made only 33.3% of their shots in the first half but led at halftime, 31-26.
A late letdown by the Bruins would become a trend.
"We just didn't finish either half," Alford said. "That was the difference in the game."
Saturday at Oregon, 7:15 p.m., Matthew Knight Arena, ESPN — The Bruins have lost three straight on the road against the Ducks, last beating them in Eugene in January 2014 on Travis Wear's put-back basket with 5.3 seconds left.