LOS ANGELES >> Before Sam Darnold led Southern California on a 13-game winning streak that made him a Rose Bowl champion and a top NFL prospect, the quarterback made his first career start against Utah last season.

And he lost.

Darnold gets a chance to right one of the few wrongs against him on Oct. 14 when the No. 13 Trojans (5-1, 1-1) host the Utes (4-1, 1-1) to decide the clear front-runner in the Pac-12 South.

“He is a phenomenal quarterback and a great athlete,” Utah coach Kyle Whittingham said of Darnold. “He is one of the best quarterbacks in the country, without a doubt.”

Darnold has rebounded thoroughly from his starting debut, which came last season under dire circumstances in Salt Lake City. The Trojans were off to a difficult beginning to Clay Helton’s first full season in charge, and the coach replaced quarterback Max Browne with the promising prospect from Orange County.

“That was his first game last year, and now he’s a quarterback that’s 14-2 and the reason we’re so successful,” Helton said.

Darnold went 18 of 26 for 253 yards, and he nearly even got the win. But Troy Williams led Utah on a 15-play, 93-yard drive culminating in the winning touchdown with 16 seconds left.

Williams grew up just south of USC’s campus in suburban Carson, and he made his first start of this season against Stanford last week in place of Tyler Huntley.

With Huntley still returning from injury, Whittingham has refused to say who will start at the Coliseum this week, even leaving open the possibility of third-stringer Cooper Bateman, but Williams is preparing with the expectation of getting a chance to shine in front of his hometown fans.

No matter who starts for Utah, Helton is aware of the challenges posed by another strong offense for the Utes, who have become near-annual contenders for the division title.

“They’re more of a conventional animal right now,” Helton said. “I’ve thought about Utah in the past, and you really go in there saying, ‘Oh gosh, I’ve got to stop the run.’ When you look at this team, they’re a lot more balanced. They’ve got a great receiver out there in (Darren) Carrington, and they’ve got two kids that they believe in spinning the ball in Huntley and Troy. They’re not one-dimensional now. They can run it or throw it anytime they want to.”

Here are more things to watch when Utah attempts to beat USC in Los Angeles for the first time since 1916, before the Coliseum opened:

>> Darnold’s time: Darnold hasn’t blown away the Pac-12 during his much-hyped second season as the starter, but Helton has stayed firmly behind a clearly talented passer making a few too many mistakes. He has passed for 1,705 yards with 12 touchdowns, but nine interceptions and a handful of key fumbles have held back the Trojans from dominating certain games.

>> Bounce back: Utah is coming off its first loss of the season, falling 23-20 to Stanford. USC beat the Cardinal 42-25 at the Coliseum earlier this year. Whittingham wasn’t thrilled with the offense as directed by Williams, who went 20 of 39 against Stanford.

>> Colliseum control: USC has won 13 straight home games in its longest streak since winning 35 straight under Pete Carroll from 2001-07. Utah’s robust alumni base in the Los Angeles area turned out for the Utes’ 52-45 win at UCLA last year, but hasn’t had anything to cheer in downtown LA since Utah joined the Pac-12.

>> Bright lights: The schools are playing a prime-time game in front of a national audience on ABC. USC doesn’t need much more exposure, but the spotlight could help the Utes as they continue building a power.

“It can be a big positive, particularly when you play well,” Whittingham said. “If you have a big showing, win the game or play very well, it can have a big impact.”

>> Poll implications: Utah would return to the rankings emphatically with a victory, while USC might get the juice to get back in the Top 10 during a season in which its only loss came on a short week on the road against unbeaten Washington State.