The Oklahoma State transfer, fighting through a nagging rib injury, sniffed out Arizona’s toss play to DJ Williams and instead of going over the blocks like he did earlier, he sliced between them. He had a free lane. He won the game, sealing a 43-41 triple-overtime victory for the No. 9 Trojans at the Coliseum on Saturday by enveloping the Arizona running back on a tackle with USC defensive back Prophet Brown during Arizona’s final two-point conversion attempt.

After the No. 9 Trojans (6-0, 4-0 Pac-12) coasted through their first three home games, winning them by an average of 42 points, Cobb soaked in the roar of the home crowd as he shouted to his celebrating teammates.

“To me, personally, I don’t want to win by 40 points. I get bored,” Cobb said. “You want that grind … that grit, man.”

USC had to grind through a 17-point deficit to keep its unblemished record intact against Arizona, making just enough plays late to erase their own mistakes that necessitated such a dramatic finish. There was the fumbled snap on second and goal from the six-yard line with 19 seconds left. The high snap on the would-be chip-shot field goal as regulation expired. All of the simple toss plays Arizona (3-3, 1-2 Pac-12) piled up against a maligned defense.

Yet after each blunder, the Trojans answered back.

“If our culture wasn’t strong enough, I think we would be sitting in here without a smile on our face now,” head coach Lincoln Riley said.

Here are four takeaways from the USC victory:

Better with time?

Riley repeats it. Players have bought into it. USC’s social media pages promote it. USC’s newest motto.

“The defense preaches ‘the longer we go, the better we get,’ ” said safety Calen Bullock, who delivered a critical pass breakup on a two-point conversion attempt during the second overtime. “We preach that every single day. I think the defense went out there and showed that.”

Although USC has tried to exorcise its fourth-quarter demons with its catchy phrase, the results haven’t been consistent. Despite building leads, USC has been locked in one-possession games as late as the fourth quarter for three consecutive weeks against Arizona State, Colorado and Arizona. Colorado nearly came back from a 41-14 deficit in a seven-point loss in Boulder during which the Trojans were outscored 14-0 in the fourth quarter.

Trojans cornerback Prophet Brown (16) and Calen Bullock (7) break up a pass during a play in overtime.

(Gina Ferazzi / Los Angeles Times)

The struggles against Arizona State and Colorado reignited conversations about USC’s underwhelming defense that gave up more than 500 yards for the second consecutive game Saturday. The criticism has finally riled up quarterback Caleb Williams, who, unprompted, backed his defensive teammates at the postgame news conference.

“We wouldn’t have won that game without the defense,” Williams said.

Williams plays to win the game

It might have been Williams’ worst game as a Trojan, but it ended with a crowning moment.

After Williams raced to the end zone and swept the ball past the inside edge of the pylon, the quarterback skipped toward the uprights, planted both feet on the ground and mimicked putting a crown on his head.

Williams finished with 219 yards and one touchdown on 14-of-25 passing. The passing total was Williams’ lowest since throwing for 180 yards at Oregon State on Sept. 24, 2022. Williams has been held to one touchdown only three times at USC, but made up for it Saturday by tying his career high with three rushing touchdowns on 41 yards.

With his NFL career still looming, Williams admitted Saturday night he doesn’t “really like to run, to be honest.” But he noticed how the Arizona defensive ends were aggressively rushing up field on passing downs and capitalized on the open lanes.

USC quarterback Caleb Williams leans across the goal line for the game-winning two-point conversion Saturday.

(Gina Ferazzi / Los Angeles Times)

“You gotta do whatever you gotta do to win the game,” Williams said, “whether it’s me passing for 400 or it’s me running for 200.”

Williams was the target of several late hits by Arizona defenders. The Wildcats had 10 defensive penalties, including two roughing-the-passer calls, both during the second half, but the extra shots didn’t deter Williams or his teammates.

“We block out the noise,” said running back Austin Jones, who scored on an 11-yard touchdown run during the second overtime. “We block out all the extra curricular stuff. We just go out there and play.”

Offensive line struggles

After center Justin Dedich lamented the USC offensive line’s lack of physicality against Colorado, the Trojans got overpowered early on the line of scrimmage against the Wildcats. USC surpassed its season high in sacks allowed in a game in just one quarter, allowing three in the second Saturday. Before their final drive of the second quarter, which started with back-to-back rushes of nine and 21 yards from MarShawn Lloyd, the Trojans had no rushing yards.

Heading into the critical drive, the Trojans brought Mason Murphy in at right tackle, replacing starter Michael Tarquin. Lloyd ran toward Murphy’s side on the first play, jump-starting the drive that ended in a touchdown pass from Williams to Kyron Hudson with two seconds left. The play salvaged a three-point halftime deficit for the Trojans after they dug themselves into a 17-point hole.

The Trojans gave up four sacks, doubling their previous season-high allowed, and Murphy remained in the game for the entire second half.

Covington’s pick sparks comeback

For the second consecutive week, a cornerback got his first start of the season and grabbed his first interception as a Trojan. Jacobe Covington’s critical interception during the second quarter that set up USC’s first touchdown was the Washington transfer’s first college pick.

Trojans cornerback Jacobe Covington poses for a photo on media day.

(Gary Coronado / Los Angeles Times)

“That’s what allowed us to get back in it,” Riley said. “That energized the entire team, the entire sideline. Obviously you don’t want to put yourself in that hole, but when you’re in it, man, you can either feel sorry for yourself or you can dig yourself out and we dug.”

Covington, who received the game ball and plans to give it to his mother, transferred after two seasons at Washington. The redshirt junior had 14 tackles last season while starting three games. After getting buried on the depth chart this season, Covington earned the starting role Saturday in place of injured sophomore Domani Jackson.

“Whenever I get my opportunity, I’m going to try to make the best of it,” said Covington, who had three tackles. “Whenever I’m out there, I’m going to do my best, help the team, that’s who I am.”

Riley said last week that small injuries have bothered the cornerback group, noting that Christian Roland-Wallace was one of the few to avoid the injury bug. Roland-Wallace used his clean bill of health to rise to the top of the depth chart and play every defensive snap against Colorado, but the Arizona transfer was sidelined for most of the second half Saturday. Playing against his former team for the first time, Roland-Wallace sustained an undisclosed injury early in the third quarter while dragging Arizona star receiver Tetairoa McMillan down after a 21-yard gain.

After the play, McMillan pulled his former teammate up to his feet.