Salt Lake City — Troy Williams threw for 270 yards and two touchdowns and ran for another score in No. 24 Utah's 31-27 comeback victory over Southern California on Friday night.

The Utes roared back in spectacular fashion with Tim Patrick catching an 18-yard touchdown pass at the pylon with 16 seconds remaining to cap a 15-play, 93-yard drive. Patrick had his third 100-yard receiving game of the season.

"USC, that's my hometown," said Williams, who is from Carson, California. "Growing up watching Reggie Bush, Carson Palmer and Mike Williams and all those dudes, just sitting at home watching on TV and imagining maybe one day I'll play with them or against them. Today was that day."

The Trojans controlled most of the game and had a 27-17 fourth-quarter lead, but Utah (4-0, 1-0 Pac-12) scored 14 straight points. USC fell to 1-3 for the first time since 2001.

Utah attempted to control the game on the ground early against the No. 98 run defense in the country, but USC tightened up and forced the Utes to win through the air.

USC's Sam Darnold threw for 253 yards and ran for a touchdown in his first career start after replacing Max Browne.

"Refused to quit, just kept fighting the entire 60 minutes," Utah coach Kyle Whittingham said. "Made play after play after play at the end there when we had to make plays.

"Nobody panicked. Just kept doing our thing."

The takeaway

USC: The Trojans are in serious trouble. There were already whispers that coach Clay Helton was on the hot seat, but blowing a 10-point lead in the final quarter may solidify that. Darnold was an upgrade, but USC is now 0-2 in conference.

Utah: Friday was the first true test for the Utes and they passed — barely. The run game started hot with 132 yards in the first half, but faded fast and continued to have ball-control issues with two fumbles. The defense allowed the most yards it has all season (466), but bowed up in the fourth quarter when the team absolutely needed it.

Injury update

Utah starting cornerback Dominique Hatfield played in his first game of the year. He'd been sidelined with an undisclosed leg injury.

The Utes lost 2015 first team All-Pac-12 tackle Lowell Lotulelei to an unknown injury before halftime and did not return.

Fancy

The Utes wore new black helmets that were individually hand painted by an artist. The design mimics a granite texture and no two are identical as each has its own serial number painted on the helmet.

Poll implications

USC: The Trojans will continue to stay out of the poll. They didn't receive a single vote last week.

Utah: The Utes could move up a couple spots depending on what happens in front of them because of a 4-0 start. A win over USC, however, won't get a lot of points from voters.

Quotable

"Watching them drive the ball down kind of crushed our soul," USC receiver JuJu Smith-Schuster said.

Up next

USC: The Trojans return home to host Arizona State (3-0, 0-0) in a Pac-12 South showdown Oct. 1.

UTAH: The Utes travel to face California (2-1, 0-0) in Pac-12 action on Oct. 1.