BERKELEY, Calif. (AP) With Sam Darnold and Southern California's usually potent offense struggling to finish drives, the defense kept getting the ball in good positions for the Trojans.

Fifth-ranked USC forced four of its six turnovers in the fourth quarter to set up a touchdown run by Stephen Carr and a TD pass by Darnold, and the Trojans won their 13th straight game by pulling away late for a 30-20 victory over California on Saturday.

''We preach it all the time,'' defensive coordinator Clancy Pendergast said. ''Turnovers are something we made a big emphasis on in the offseason. As much as we can, get our offense the ball back. The best place for us is on the sideline, so the more we can be over there the better.''

Jack Jones intercepted two passes, Josh Fatu and Christian Rector each forced fumbles on sacks and Chris Hawkins and Ykili Ross added picks to give USC (4-0, 2-0 Pac-12) its 14th straight win in the series against the Golden Bears (3-1, 0-1).

But this was one of the tightest matchups in years as the game was tied early in the fourth quarter before USC took over on the defensive end after Chase McGrath's third field goal put the Trojans up 16-13.

''We came in at halftime, took a deep breath, made some changes and said, `Hey, let's elevate our level of play,''' coach Clay Helton said. ''I thought everybody, the whole team, elevated our play in the second half.''

Fatu knocked the ball out of Ross Bowers' hand and Uchenna Nwosu recovered the fumble at the 3. Carr ran it in two plays later from the 2 to make it 23-13. Ykili Ross then intercepted Bowers' pass on the next possession, setting up Darnold's 4-yard TD pass to Deontay Burnett that put away the game.

''It's hard to win when you keep giving the other team the ball,'' Bowers said.

Darnold threw for 223 yards and two touchdowns but also had an interception as Cal's defense forced him out of the pocket numerous times.

''I felt a little bit of pressure,'' Darnold said. ''I think it's mostly our fault for not connecting on some of those deep balls and taking advantage of those opportunities when they come our way.''

THE TAKEAWAY

SOUTHERN CALIFORNIA: The Trojans struggled for much of the game without starting RB Ronald Jones (ankle) and WR Steven Mitchell (groin) but managed to pull away late in their first road game of the season. But there were some issues with two first-half turnovers in Cal territory and a failed fourth-down run in the third quarter that prevented USC from pulling away earlier.

CALIFORNIA: A sequence on the opening drive of the second will haunt the Bears. Patrick Laird dropped a potential TD in the end zone when he lost it in the sun and Matt Anderson then missed a 29-yard field goal that kept the game tied at 13. Bowers struggled after that, finishing 22 for 50 for 303 yards with one touchdown, four interceptions and two lost fumbles.

POLL IMPLICATIONS

A win against an unranked team should do little to alter USC's poll position.

SECOND-HALF SWING: Cal was on the other side of a big second half this game. After overcoming halftime deficits to win the first three games and outscoring the opposition 57-13, the Bears were outscored 17-7 in the second half with their only TD coming late after the game had been decided. The fourth quarter has been a strength for the Trojans, who have outscored their opponents 62-31 in the final quarter.

TRUSTED KICKER: After kicking the game-tying field goal on the final play of regulation and the game-winner in double overtime last week against Texas, walk-on McGrath made three more against Cal from 37, 34 and 46 yards.

''You're starting to gain confidence as a coach and you can see his confidence just beaming right now,'' Helton said.

FOURTH DOWNS: Cal was aggressive on fourth downs, converting two tries on its first touchdown drive and then another one in the third quarter that made the Bears 9 for 10 on the season at that point. But Wilcox then tried a fourth-and-4 from the USC 42 late in the third quarter that was stopped on an incomplete pass. USC used the short field to drive for the go-ahead field goal and didn't look back.

''We felt like we had a good play. Obviously, we didn't execute it,'' Wilcox said. ''We were playing to win, that was the reason we went for it there.''

UP NEXT

SOUTHERN CALIFORNIA: Visits No. 18 Washington State on Friday.

CALIFORNIA: Visits No. 24 Oregon on Saturday.

---

More AP college football: collegefootball.ap.org and twitter.com/AP-Top25

Copyright 2017 by STATS. Any commercial use or distribution without the express written consent of STATS is strictly prohibited.