By Bob Baum

TUCSON, Ariz. (AP) - Freshman linebacker Myles Jack played offense, too, rushing for 120 yards on his first six carries of the season, including a 66-yard touchdown run to help No. 16 UCLA beat Arizona 31-26 Saturday night.

On defense, Jack had eight tackles and recovered Ka'Deem Carey's fumble in the UCLA end zone as the Bruins won in Tucson for the first time since 2003.

Brett Hundley passed for two touchdowns and ran for another as UCLA (7-2, 4-2 Pac-10) stayed a game behind first-place Arizona State in the Pac-12 South. Carey rushed for 149 yards on 28 carries for the Wildcats (6-3, 3-3), running his school-record string of consecutive 100-yard rushing games to 12.

Hundley threw a 66-yard touchdown pass to Shaq Evans on UCLA's first offensive play. Evans also had a 4-yard scoring catch.

Arizona's B.J. Denker had a pair of fourth-quarter touchdown passes to Nate Phillips.

The Bruins were without starting running back Jordon James , who aggravated a right ankle injury a week earlier against Colorado, and they turned to the 18-year-old Jack to fill in at crucial times.

A pass interference penalty on third down kept Arizona's 8-play, 88-yard TD drive alive and Carey's runs of 22 and 24 yards set up Denker's 15-yard touchdown pass to Nate Phillips that cut UCLA's lead to 24-19 with 11:46 to play. The two-point conversion pass failed.

Then on third-and-1 from the UCLA 24, Jack burst through the line and down the right sideline 66 yards for a touchdown to make it 31-19 with 10:46 to go.

But Arizona quickly responded, going 75 yards in 2:44, Denker throwing 14 yards to Phillips to cut the Bruins' lead to 31-26 8:02 from the finish.

The Wildcats got the ball twice more but couldn't move it. Ishmael Adams ' interception of Denker's pass on fourth down from the Arizona 15 sealed it with 1:46 to play.

On UCLA's first play on offense, Hundley connected with the streaking Evans, who got behind Arizona's Jonathon McKnight for 66 yards and a touchdown. The Bruins led 7-3 and never trailed again.

After the subsequent kickoff, the Wildcats drove deep into UCLA territory, but on fourth and a foot from the 15, Carey was stopped for a 1-yard loss and the Bruins took over. Hundley had a 17-yard run and scrambled for a 15-yard touchdown to cap UCLA's 12-play, 84-yard scoring drive to make it 14-3 with 1:23 still left in the first quarter.

The Bruins helped Arizona to its first touchdown when they tried a fake punt from their own 25. Sean Covington overthrew the wide open Jack on the play, and the Wildcats scored four plays later, Carey on a 4-yard run to cut it to 14-10 with 12:55 left in the half.

It stayed that way until UCLA, behind the running of Jack, went 90 yards in 16 plays. McKnight deflected Hundley's pass in the end zone, but Evans was able to bring it down and drag his toes inbounds for the touchdown with 16 seconds left in the half and give the Bruins a 21-10 lead at the break.

UCLA added a 34-yard field goal by Ka'imi Fairbairn on its first possession of the second half, then Arizona drove from its 12 to first-and-goal at the Bruins 5. Carey took the ball up the middle and was slammed by the defense, sending him into a head-first flip. He lost the ball just before crossing the goal line, and Jack recovered in the end zone for a touchback and it remained a two-touchdown lead.