PASADENA — For most of the season, the ninth-ranked UCLA football team has been able to make up for its suspect pass defense.

The Bruins, however, got off to a slow start offensively Saturday night and the woes were exacerbated by Arizona quarterback Jayden de Laura.

The signal caller found true freshman receiver Tetairoa McMillan for a 17-yard go-ahead touchdown on fourth down more than midway through the fourth quarter and UCLA was unable to finish off its final drive as time expired in a 34-28 loss at the Rose Bowl.

On top of his 315 yards passing and three total touchdowns, de Laura ran circles on multiple occasions to escape the grasp of the Bruins’ pass rush. Just as de Laura slipped through their hands, UCLA (8-2, 5-2 Pac-12 Conference) let a golden opportunity slip away on a night No. 6 Oregon lost to No. 24 Washington to create a possible logjam atop the conference.

Arizona (4-6, 2-5 Pac-12) generated 436 yards of total offense and won in Pasadena for the first time since 2010.

First quarter

8:47, Arizona: RB Michael Wiley 10-yard TD run (PAT GOOD, Tyler Loop), 7-0 Arizona

3:01, Arizona: QB Jayden de Laura to RB Michael Wiley, 22-yard TD (PAT GOOD, Tyler Loop), 14-0 Arizona

Second quarter

13:12, UCLA: RB Zach Charbonnet 1-yard TD run (PAT GOOD, Nicholas Barr-Mira), 14-7 Arizona

8:11, UCLA: QB Dorian Thompson-Robinson to TE Hudson Habermehl, 51-yard TD (PAT GOOD, Nicholas Barr-Mira), 14-14

2:01, Arizona: QB Jayden de Laura 3-yard TD run (PAT GOOD, Tyler Loop), 21-14 Arizona

Third quarter

3:38, UCLA: RB Zach Charbonnet 1-yard TD run (PAT GOOD, Nicholas Barr-Mira), 21-21

Fourth quarter

13:20, Arizona: PK Tyler Loop 35-yard field goal, 24-21 Arizona

10:22, UCLA: RB Zach Charbonnet 5-yard TD run (PAT GOOD, Nicholas Barr-Mira), 28-24 UCLA

6:34, Arizona: QB Jayden de Laura to WR Tetairoa McMillan, 17-yard TD (PAT GOOD, Tyler Loop), 31-28 Arizona

1:07, Arizona: PK Tyler Loop 23-yard field goal, 34-28 Arizona

Before the end of the third quarter, Arizona converted on a fourth-and-3 with a 30-yard pass from de Laura to receiver Jacob Cowing to get to the UCLA 11-yard line. Cowing, lined up in the slot, had the mismatch with Bruins linebacker Darius Muasau lined up across from him and made the catch in open space.

UCLA edge rusher Grayson Murphy chased and finally corralled a wild running de Laura for a sack and loss of 14 yards at the start of the fourth and Arizona settled for a 35-yard field goal to take a 24-21 lead.

Then, with 6:34 to play, UCLA again gave up a fourth-and-4 conversion on de Laura’s go-ahead touchdown to McMillan to take a 31-28 lead.

On the game’s final drive, UCLA reached the Arizona 29 as quarterback Dorian Thompson-Robinson heaved a pass intended for receiver Jake Bobo. The Bruins then took four consecutive shots at the end zone, the last a throw to Bobo in the back of the end zone that was just out of reach of Bobo’s dive and outstretched arms as time expired.

Thompson-Robinson completed just four of his last 12 throws.

After missing last week’s win at Arizona State, UCLA running back Zach Charbonnet returned and ran for 181 yards and three touchdowns to go with a team-high nine catches for 38 yards.

Charbonnet jumpstarted a UCLA offense that trailed 14-0 through a quarter, its offense lifeless as Arizona had a 137-19 advantage in total yards at one point.

The Bruins got back in the game on a 1-yard Charbonnet run, and after forcing a punt on the next possession UCLA had to start from its own 1-yard line.

Five plays later, Thompson-Robinson found tight end Hudson Habermehl in space and the 6-foot-6 target split two Wildcats defensive backs to break free for a 51-yard touchdown to tie the game 14-14 with 8:11 left in the half.

The response wiped out a sluggish start and got the Bruins back on track in a hurry to avoid what could have been further disaster.

The Wildcats pulled back ahead 21-14 on de Laura’s 3-yard touchdown run and the Bruins were looking to answer back going into the break. On fourth-and-2 from the Arizona 26, UCLA was flagged for a false start out of a timeout with 28 seconds left. On the next play, Thompson-Robinson fumbled on the Arizona 23 to close the half.

Charbonnet’s 5-yard touchdown in the fourth gave UCLA its lone lead at 28-24 with 10:22 to play.

However, just as he was outstanding, Charbonnet dropped a crucial pass on third-and-6 and Thompson-Robinson airmailed receiver Josiah Norwood on the next throw to turn the ball over on downs with 5:47 left while trailing 31-28.

Arizona took advantage with placekicker Tyler Loop’s 23-yard field goal to push the lead to 34-28.

Like he had done in the previous loss at Oregon, UCLA safety Mo Osling III led the team with 12 tackles — and that’s never a good sign for the back end of a defense.

Twin edge rushers Gabriel and Grayson Murphy and defensive tackle Jay Toia all came up with sacks, as UCLA had success bringing pressure but couldn’t keep de Laura contained to the finish of several plays.

Trailing 24-21 early in the fourth, Thompson-Robinson made a huge lead block to help spring Charbonnet free for a 36-yard run to set up his 5-yard score.

UCLA chased and chased and chased de Laura some more, recording three sacks. However, he escaped significantly more times than he was brought down and several of them led to throws on the run to extend drives.

The Wildcats were 5 of 12 on third down and 2 of 2 on fourth down, and de Laura wore down an already weak Bruins pass defense that was without starting cornerback Devin Kirkwood (left wrist).

On top of that, the UCLA offense failed to give the defense the early cushion it had provided so many other times this season. The combination of the two made for a combustible mix and the Bruins never looked like they had full control of the game, trailing for most of it.

Passing

Dorian Thompson-Robinson: 26 of 39 for 245 yards, TD

Rushing

Zach Charbonnet: 24 carries for 181 yards, 3 TDs

Dorian Thompson-Robinson: 11 carries for 24 yards

Colson Yankoff: 2 carries for 15 yards

Receiving

Zach Charbonnet: 9 catches for 38 yards

Jake Bobo: 5 catches for 61 yards

Hudson Habermehl: 3 catches for 64 yards, TD

Kam Brown: 3 catches for 58 yards

Colson Yankoff: 2 catches for 9 yards

Josiah Norwood: 2 catches for 9 yard

Logan Loya: 1 catch for 5 yards

Keegan Jones: 1 catch for 1 yard