The power went out late in the first half with UCLA leading Texas by 11 points. The Bruins were never the same afterward.
J'Covan Brown scored 22 points, Myck Kabongo added 13 and Texas shot 71 percent in the second half to win 69-59 on Saturday in the game delayed nearly 13½ minutes by the outage at the aging Los Angeles Sports Arena.
"Thank God for those lights," Kabongo said. "It was a turnaround."
The Longhorns (5-2) benefited from the power surge that affected the area around the arena, south of downtown. After the lights came back on, they outscored UCLA 9-4, including five by Brown, to end the half trailing 34-28.
"Coach said, 'Keep wearing them down and keep hitting them with screens. They're going to get tired running through them,'" Brown said.
Kabongo added, "We were hitting them, and no one wants to get hit. We sent a message that if you're going to come down here, we're going to hit you. Our guys put a body on someone."
Lazeric Jones scored 21 points and Travis Wear added 13 for the Bruins (2-5), who equaled their worst start since 2002-03, Steve Lavin's last season as coach.
"We've got to get on the winning way here," said Bruins coach Ben Howland, who fell to 0-3 against Texas.
The Longhorns opened the second half on a 12-6 run to tie the game 40-all. They took their first lead on Kabongo's open layup that keyed an 11-3 spurt. He followed with a fast-break layup off his own steal, then Sheldon McClellan hit a 3-pointer, Jonathan Holmes made a free throw and Kabongo capped the scoring with a 3-pointer that extended Texas' lead to 51-43.
"As the game wore on, especially the last couple minutes of the first half, we got a little bit tougher. We ran our offense better," Texas coach Rick Barnes said. "Early in the first half, we just weren't moving the ball."
The Bruins went 7:10 without a field goal during most of the Longhorns' run. They got back into the game on Jones' 10-0 run that included consecutive 3-pointers to close the Bruins to 56-53. But they got no closer.
The Longhorns ran off seven unanswered points, capped by Brown's 3-pointer, to push their lead to 63-53.
The Bruins were leading by 11 points when the lights went out with 3:59 to play in the first half at the arena, where UCLA is playing most of its home games this season while Pauley Pavilion undergoes a major renovation.
As some of the old-style lights powered back on, the teams shot free throws.
With all but the lights directly above the court back on, the teams resumed play. Texas' Alexis Wangmene returned to the free-throw line and made both shots before UCLA's Joshua Smith missed a layup in the dimmer conditions.
The referees asked both coaches if they wanted to wait an extra 10 minutes for the TV lights to come back on.
"I said, 'Well, I can't really see the rim, but the way we're shooting I don't think it could hurt us,'" Barnes said. "We made a couple plays at end of the first half. The second half we really executed well offensively."
Eventually, all the lighting was restored.
The Bruins were perfect to start the game, hitting their first six shots as all five starters scored en route to a 17-6 lead. It was the first of four 11-point leads they owned in the half as UCLA outscored the Longhorns 20-12 in the paint.
Reeves Nelson and Smith continue to struggle after being key players for the Bruins last season.
Nelson, who has gone from starting to coming off the bench after a brief suspension, was scoreless with three rebounds and two turnovers for the Bruins. He didn't play at all in the second half.
"He had a couple practices that weren't great leading up to this game," Howland said. "He hasn't played how he's capable of playing, and a lot of it is his mental attitude. You play in the game how you practice."
Smith, who tips the scales at more than 300 pounds, has yet to improve his conditioning. He had six points, three rebounds and a steal in 12 minutes to go with two fouls.
"Josh has got a lot of work to do with his conditioning, and it's got to be extra work outside of practice," Howland said.