USC true freshman running back Ronald Jones II broke off a 74-yard touchdown run in the fourth quarter and ran for a career-high 177 yards to help USC put away pesky Arizona 38-30 at the Los Angeles Coliseum on Saturday night.

The Trojans (6-3 overall, 4-2 Pac-12) won their third consecutive game and stayed alive in the Pac-12 South under interim head coach Clay Helton.

USC didn't lead until the first snap of the fourth quarter, as running back Justin Davis scored on a 9-yard run. The Trojans drove for the go-ahead score after stuffing Arizona on fourth-and-2 from midfield.

Jones shredded tackles and weaved downfield on his long touchdown run with 9:24 to go after the Wildcats (5-5, 2-5) had closed within 24-23. Jones finished with 19 carries.

USC receiver JuJu Smith-Schuster, playing with a soft cast on his right hand five days after undergoing surgery to repair a fracture, caught eight passes for 138 yards, including a 72-yard touchdown. He left the game with 8:50 to go in the third quarter because of cramps but returned to make a key third-down catch as the Trojans drove to take a 38-23 lead on a 16-yard run by Davis with 2:36 left.

Arizona quarterback Anu Solomon threw a 4-yard touchdown pass to receiver Cayleb Jones with 11 seconds left for the final margin. The ensuing onside kick went out of bounds.

USC quarterback Cody Kessler completed 22 of 36 passes for 243 yards and two touchdowns. Solomon was 31 of 46 for 352 yards, with three touchdowns and one interception.

Arizona allowed USC to gain just 12 first-quarter yards and then took a 14-0 lead on the first play of the second quarter on a 3-yard slant pass to receiver David Richards.

Arizona was driving to go up 21-3, but safety John Plattenburg picked off a floating pass from Solomon near the goal line. One play later, Kesser launched a deep pass to Smith-Schuster, who beat a safety and scored on a 72-yard reception.