UCLA pressed early, then simply put the pressure on Nebraska after the Bruins' slow start.
Brett Hundley passed for 294 yards and three touchdowns as No. 16 UCLA overwhelmed No. 23 Nebraska with four third-quarter touchdowns for a 41-21 victory on Saturday at Memorial Stadium.
UCLA (2-0) trailed, 21-3, in the second quarter, but scored touchdowns on five of six possessions to gain momentum after Nebraska capitalized on two turnovers to take an early lead.
"I felt that the first quarter and a half of the game, we were trying so hard -- so hard -- to try and make something happen good, that we were tight," UCLA coach Jim Mora said.
"In the second quarter, there at the end, we kind of relaxed and made plays, and we kind of found our rhythm again."
The Bruins, who scored 41 of their 58 points in the second half of a season-opening victory over Nevada, had 236 yards of offense in the third quarter, when they scored their four touchdowns over a seven-minute span.
"We came in at halftime, (and) not a lot of adjustments had to be made," Mora said. "Really, just an adjustment in our mindset, which was to relax, play with confidence, go out and have fun playing the game and let it roll."
Taylor Martinez passed for 203 yards for Nebraska (2-1), but was sacked twice and finished with minus-13 yards rushing, as UCLA held Nebraska to 123 rushing yards.
The senior quarterback threw three touchdowns passes, including two after UCLA turnovers.
Nebraska's defense, which made strides last week in a rout of Southern Miss after allowing 602 yards to Wyoming in the opening week, lost steam after a strong early start.
The Huskers missed tackles in open space and allowed seven plays of 12 yards or more in the third quarter alone.
"We got beat in every phase of the game in the second half," Nebraska coach Bo Pelini said. "I think we showed a little bit of what we're capable of as a football team in the first half, but in the second half, we got away from fundamentals. It's nothing magical."
The game turned late in the second quarter, when Hundley, on third-and-12 from the UCLA 39, twice avoided near sacks, eluding Nebraska freshman defensive end Avery Moss, and ran 13 yards to keep the drive alive.
That series ended with Paul Perkins scoring on a 10-yard run up the middle with 57 seconds remaining in the half, pulling the Bruins to within 21-10 at halftime.
UCLA, with a stiff wind at its back in the second and third quarters, didn't stop there.
James Jordon scored on a three-yard run to cap a 10-play, 89-yard drive to make it 21-17.
The Bruins' next three touchdown drives lasted 1:01, 1:49 and 45 seconds, and UCLA, a year after compiling 653 yards in a victory over Nebraska, was on its way to 504 totals yards.
"When things started going the other way on us, we lost a sense of what our job was," Pelini said. "Some of the basic things that we were doing through one quarter, two quarters, two and a half quarters, we stopped doing.
"You have to be able to refocus and keep your composure to do your job and execute your football."
Nebraska had an early surge of momentum.
Stanley Jean-Baptiste set the tone with his third first-quarter interception of the season. The senior cornerback sat on a route and returned Hundley's pass 34 yards to the UCLA 28-yard-line to end the Bruins' second series of the game.
Four plays later, Martinez threw a fade pass to Quincy Enunwa in the end zone for a 7-0 Nebraska lead with 9:45 to play in the first quarter.
Leading, 7-3, Nebraska put together its only sustained drive of the game -- a 17-play, 92-yard series that lasted 6:34 and ended with Martinez's 14-yard touchdown pass to Enunwa.
Nebraska went ahead, 21-3, when Martinez hit Kenny Bell on a 22-yard touchdown pass, a short series set up after the Huskers recovered a fumbled punt snap at the UCLA 26-yard line.
NOTES: With 114 yards of total offense in the first half, Taylor Martinez moved past 10,000 career yards of total offense. He is the ninth player in Big Ten history with 10,000 yards of total offense. ... Nebraska players wore a "36" decal on the back of their helmets, and UCLA players and coaches wore a "36" patch on their uniforms and shirts in remembrance of UCLA walk-on receiver Nick Pasquale, who died after he was struck by a car last weekend. Nebraska students released 200 blue and gold balloons during a moment of silence before the game to remember Pasquale. ... The collapse was Nebraska's biggest at home since losing a 12-point first-half lead to Washington in 1991.