TUCSON, Ariz. (AP) -- When Utah quarterback Tyler Huntley went down with a shoulder injury in the second quarter, the Utes had an experienced and reliable alternative ready.
Troy Williams, a senior who started 13 games last season, came on and guided the No. 23 Utes to a 30-24 victory over Arizona on Friday night in the Pac-12 opener for both schools.
"We're in a good place quarterback-wise," Utah coach Kyle Whittingham said. "Obviously we want Tyler back as soon as possible, but Troy won nine games for us last year, and he was ready."
Not that was easy.
Chris Hart recovered Arizona quarterback Brandon Dawkins' fumble at Utah's 20-yard line with 2:33 left to preserve the victory.
Wildcats coach Rich Rodriguez didn't think it was a fumble.
But, Dawkins said, "You've got to go with what the refs call and that's what they called. I shouldn't have made it close. I should have held the ball a little tighter and not let them get a late strip there. So that's on me regardless."
Utah (4-0) led throughout and was up 30-17 late in the fourth quarter, but Dawkins threw a 30-yard TD pass to Tony Ellison with 2:44 to play, cutting the lead to six. The subsequent onside kick attempt bounced downfield, and Arizona's Shawn Poindexter recovered at the Utes' 35.
On the next play, Dawkins ran 15 yards to the 20 but fumbled, and Hart recovered.
The Wildcats (2-2) committed five turnovers, including three interceptions by Dawkins.
Utah scored a touchdown on its first possession, and then Arizona twice cut the lead to three - the last time at 20-17 on J.J. Taylor's 7-yard TD run with 4:38 left in the third quarter.
But 2 ½ minutes later, with Arizona deep in its own territory, Dawkins threw short over the middle and Javelin Guidry intercepted, returning it 14 yards for a touchdown that made it 27-17.
Huntley completed 8 of 9 passes for 98 yards before he left with an injured shoulder after being sacked by Tony Fields with 8:45 left in the half.
Taylor fumbled at Utah's 1-yard line in the second quarter, and the Utes drove all the way to the Wildcats 8. Six plays into the long drive, Huntley was injured and Williams - who started 13 games last season - took over. On his first play, Williams connected on a 40-yard pass to Darren Carrington, helping to set up one of Matt Gay's three field goals, this one from 26 yards, to put the Utes up 13-3 with 5:39 left in the half.
"I prepare like I'm the starter every week," Williams said. "I'm working hard every day. When my number is called I make sure I'm ready to go in. (The play) got me into things. Got me in a groove a little bit. I wanted to play smart football. I didn't want to force anything."
Utah grabbed a quick 7-0 lead on its first possession with a six-play, 73-yard scoring drive. Huntley threw 8 yards to Samson Nacua for the touchdown.
After Gay's second field goal, Arizona answered. Wide receiver Shun Brown gained 22 yards on an end around to ignite an 11-play, 75-yard drive. Dawkins scored from 1-yard out, and Utah's lead was down to 13-10 at the half.
In the third quarter, Williams passed 37 yards to Demari Simpkins to the Arizona 2 to set up Sunia Tauteoli's 1-yard touchdown run, stretching Utah's lead to 20-10 with 9:46 left in the quarter.
A targeting penalty on Utah safety Marquise Blair against Dawkins led to Taylor's 7-yard touchdown run that made it a three-point game again, 20-17, with 4:38 still to go in the third. Blair was ejected and also must sit out the first half of Utah's Sept. 7 game against Stanford.
Utah: The Utes stayed unbeaten but lost their sophomore starting quarterback. Fortunately for them, they have an experienced backup and a week off before returning to conference play.
Arizona: The Wildcats were in the game most of the way but were undone by the avalanche of turnovers.
Utah: The Utes have next weekend off before playing their conference home opener Stanford.
Arizona: The Wildcats also have a bye next weekend. They return to play Oct. 7 at Colorado.
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