TUCSON, Ariz. -- UCLA quarterback Brett Hundley played what has become his usual steady game and Myles Jack injected an unexpected spark to help the No. 16 Bruins remain in contention for the Pac-12 South title Saturday.
Hundley accounted for three touchdowns, but it was the two-way play of Jack, a freshman, that provided the edge in the Bruins' 31-26 victory over Arizona at Arizona Stadium.
Jack rushed for 120 yards on his first six carries of the season, and his 66-yard touchdown with 10:46 remaining gave UCLA a 31-19 lead. He also had eight tackles and recovered a fumble in the end zone to blunt an Arizona scoring drive.
"He played huge for us. The nation saw," Hundley said.
Arizona coach Rich Rodriguez said, "The guy is a great athlete. He's a great player. We tried to recruit him as a running back, as did most teams in the country."
Quarterback B.J. Denker threw two touchdown passes to Nate Phillips. Ka'Deem Carey, the leading rusher in FBS, had 149 yards and a touchdown as Arizona (6-3, 3-3) had a three-game winning streak broken. Carey had his 11th straight 100-yard game.
Denker's 14-yard scoring pass to Phillips make it 31-26 with 8:02 left, but Arizona did not get a first down on its final two possessions. UCLA cornerback Ishmael Adams sealed the game with a fourth-down interception with 1:46 remaining.
Hundley completed 18 of 25 passes for 227 yards and two touchdowns and added 56 yards rushing. He has 18 touchdown passes and seven touchdown runs this season, and he has accounted for at least two touchdowns in all but one game.
"We played hard, didn't play well," Rodriguez said. "The effort was good. Effort is not good enough. There has to be execution. You can't tackle a quarterback. You give up a 66-yard run. It's ridiculous."
UCLA (7-2, 4-2) is one game behind No. 23 Arizona State (7-2, 5-1) in the Pac-12 South, and the two will meet Nov. 23 in Los Angeles.
Wide receiver Shaquelle Evans caught both touchdown passes, including a 66-yarder on the Bruins' first play from scrimmage, for a lead they never relinquished.
Denker completed 20 of 33 passes for 186 yards, and with 82 yards rushing set a school season record for rushing yards by a quarterback with 645.
"We didn't execute when we got in the red zone," Denker said. "They were asking for us to take the game, but we couldn't."
Jake Smith had two field goals for Arizona. He kicked a 44-yarder on the Wildcats' first possession before Hundley and Evans connected on the next play from scrimmage.
Hundley stepped out of two tackles and around several others on a scrambling 15-yard touchdown run to cap an 84-yard drive for a 14-3 lead with 1:23 remaining in the first quarter. Hundley completed all seven of his passes for 98 yards and rushed for 32 yards in the first quarter.
After UCLA punter Sean Covington threw an incomplete pass on a fake punt from his 25 on the Bruins' next series, Carey scored on a 4-yard run four plays later to make it 14-10.
"I probably screwed with our momentum by calling that fake punt," UCLA coach Jim Mora Jr. said.
Evans' 4-yard scoring reception made it 21-10 at the half, and Ka'imi Fairbairn kicked a 34-yard field goal early in the third quarter.
The Wildcats had a chance to close within a touchdown midway through the third quarter, but Carey fumbled as he dived at the 1-yard line attempting to score. The ball rolled into the end zone and Jack recovered with 6:31 left in the third quarter.
"I'm just tying to get in the end zone," Carey said. "Jump in the air, close my eyes, take a leap. They just knocked it out. I'm looking to the next game."
Smith kicked a 27-yard field goal and Denker threw a 15-yard scoring pass to Phillips to make it 24-19 before Jack's scoring run around tight and on a third-and-1 on UCLA's next series.
"We have always talked about using Jack (on offense), but the question is how much do you give our young players to do and at what point do they become saturated and lose their effectiveness," Mora said.
NOTES: Hundley's father, Brett Sr., was a running back at Arizona from 1982 to 1986 and lettered in 1986. ... UCLA will play its final three regular-season games in Los Angeles at home against Washington on Nov. 15 and Arizona State on Nov. 23 before facing USC in the Coliseum on Nov. 30. ... The teams traded lopsided victories the last two seasons -- UCLA won 66-10 in 2012 and Arizona won 48-12 in 2011, the last meeting in Tucson.