USC had trailed by 18 points in the second half Saturday. After rallying all the way back, the Trojans fell behind again by 2 points in the final minute, but all of that only served to put this team in familiar -- almost comfortable -- territory.

Backs against the wall, game on the line, a fan base teetering on the edge of an apoplectic uproar.

"At this point, we've been through that situation so many times I feel like everyone kind of has their cool and just has that experience from those other games -- it really helps," quarterback Kedon Slovis would say afterward. "This is probably the most difficult situation we've had time-wise, but none of the guys seemed fazed and that definitely helps when you're in that pressure situation."

Indeed, the Trojans have thrived in the tensest of moments this fall, and they'd do it again Saturday evening in the Rose Bowl while needing only three big plays in that final minute to seize a momentous 43-38 win over rival UCLA.

Erasing that 18-point second-half deficit marked USC's biggest comeback win since 2005.

RELATED: First-and-10: The major reactions and reflections from USC's wild win

The Bruins had taken a 38-36 lead with 52 seconds left on a Nicholas Barr-Mira 43-yard field goal.

But they'd have no time to celebrate the go-ahead score. Moments later, freshman Gary Bryant Jr. was fielding the ensuing kickoff right in front of the goal line and racing 56 yards across midfield.

As if that wasn't enough of a jolt, Slovis saw advantageous coverage on the outside on the next play and checked to a deep pass down the right sideline that Tyler Vaughns corralled in his familiar acrobatic way for a 35-yard gain.

And on the very next play, Slovis fired a fade to Amon-Ra St. Brown in the left side of the end zone -- just like they did a week ago, the ball placed perfectly into the receiver's hands before the defensive back could even turn around.

That was how the Trojans' latest dramatic come-from-behind win ended, but the ending is only the beginning of this story.

This season had started with USC overcoming a 13-point deficit vs. Arizona State in the final 3 minutes. It continued with another game-winning drive in the final 1:35 to avoid an upset at Arizona. Somewhere along the way, it just became ingrained in the DNA of this team that no matter what, these Trojans were always within range.

"The entire second half I never saw one kid let up, one kid quit fighting and just down the stretch just make play after play after play," coach Clay Helton said. "Great college football game. ... I have some special memories in this stadium, but this year in 2020, with this team, that's about as special as it gets."

USC moves to 5-0 with the win, had already clinched the division title by virtue of Colorado's loss earlier in the day and will host Washington (or Oregon, if the Huskies' COVID situation precludes them from playing) in the Pac-12 championship game Friday in the Coliseum.

But back to Saturday ...

USC's defense was not at its best for much of the night. The early-season tackling issues resurfaced glaringly and it seemed like the Trojans just might not have enough answers this time.

UCLA (3-3) pushed its lead to 28-10 early in the third quarter when Demetric Felton pinballed off a Trojans defender and broke away for a 40-yard gain to the USC 25-yard line. Four plays later, Brittain Brown rushed in for the 15-yard touchdown as the deficit swelled to its largest peak.

The chatter was getting louder -- on message boards, social media, in living rooms, etc. The Trojans had a prime opportunity to maximize this pandemic-shortened season and they were going to squander whatever momentum had been built to this point -- against their crosstown rivals no less.

Except, that just doesn't fit the narrative of this season, this team.

So Slovis capped the next drive with a 38-yard touchdown to Vaughns down the right sideline as the redshirt senior receiver extended his arms to bring in the score.

The Bruins then botched a punt on the next series, never getting the kick off and taking a 13-yard loss to hand the ball to USC 31 yards from the goal line. Slovis would need to complete three third-down passes, including a 3-yard slant to St. Brown for the touchdown, but suddenly it was a 28-23 game.

But the point of most peril was still to come.

After outside linebacker Drake Jackson engulfed Felton for a stop on fourth-and-1 from the Bruins' own 49, it seemed like the Trojans were turning the game to their favor one big play at a time.

And then the momentum vanished in an an instant -- Slovis tossed a third-and-10 pass to the sure-handed St. Brown, who was set to have enough for the first down, expect he let it bounce through his hands and right into the arms of UCLA's Stephan Blaylock for an interception. One play later, Bruins tight end Greg Dulcich got behind the defense and reeled in a 69-yard touchdown from Dorian Thompson-Robinson.

Just like that, the Trojans were back down 35-23 in the final minutes of the third quarter, and again it looked like maybe this time they simply wouldn't be able to counteract their blunders with enough big plays. If this was a 12-round boxing match, the Trojans were knocked down again in the ninth round and it was becoming a question of how many blows they could take.

Except, again, nobody has truly been able to knock this team out yet -- the Bruins would be no different.

Running back Vavae Malepeai scored a 10-yard touchdown on third-and-5 to cut the deficit to 35-30, and moments later safety Talanoa Hufanga jumped in front of a route to interception Thompson-Robinson and bring it all the way into the end zone.

A block-in-the-back penalty on Nick Figueroa negated the touchdown, but Hufanga's fourth interception in four games was pivotal nonetheless. After back-to-back offsides penalties on UCLA turned third-and-10 into a first down, Slovis rolled to his right and fired into the middle of the end zone for a 9-yard touchdown to Drake London. The two-point conversion failed, but USC led 36-35 with 8:09 left.

The Trojans would just need one more comeback still after that late Bruins field goal, but having to win this one in the final minute (with no timeouts) only seemed appropriate and a befitting punctuation as USC managed to inject maximum drama into this five-game mini regular season.

"I knew if we just had one more opportunity they would make something happen -- that's who this team is," Helton said. "And as soon as we called timeout after third down [before UCLA's field goal] and there was 52 seconds left, I said to myself it doesn't matter if they make this or not -- there's an opportunity there for our guys."

The USC defense gave up 549 yards, but it forced three more turnovers and again showed a penchant for big plays in the big moments. Hufanga finished with 17 tackles, 2 tackles for loss, the interception and a forced fumble, Jackson had 2.5 tackles for loss and numerous other QB pressures and safety Isaiah Pola-Mao had a big interception on a ball he deflected at the line and dove to corral.

Slovis wasn't his best at times early, but he finished 30-of-47 passing for 344 yards, 5 touchdowns and 2 interceptions (one being the drop by St. Brown).

"I've always thought great quarterbacks shine when the game's on the line, and I've watched No. 9 in three situations just do what championship quarterbacks do," Helton said. "He's done it against this league now his whole career -- I think he's 12-1 now as a starting quarterback in this league. He's done a phenomenal job."

Malepeai, meanwhile, became USC's first 100-yard rusher this season, carrying it 19 times for 110 yards and a touchdown.

And the receivers starred again. Vaughns finished with 8 catches for 128 yards and a TD, London had 5 catches for 97 yards and 2 TDs (including a 65-yard score early in the game in which he broke at least six tackles) and St. Brown caught 10 passes for 73 yards and 2 TDs.

In the biggest moments, though, is where Slovis always seems his best. He's been almost perfect in the Trojans' three late-game comeback situations, and in this case, Helton talked about the "courage" his QB showed to make two audibles and check into different plays on the 35-yard strike to Vaughns and the TD to St. Brown.

Coach and QB then shared a fun exchange reflecting back on that sequence.

"What an unbelievable check by Kedon on the play to TV to send him deep. He made me nervous on the fade, but he's got the courage of a damn lion with the RPO. It was fun to watch," Helton said.

Said Slovis: "Coach said on the sideline, 'If you see man, check it' so we checked a shot to Tyler first. I overthrew him earlier in the game so I just wanted to give him a chance to make a spectacular catch. And then on the goal line, we saw man again -- we had a run called, but I checked it over to Amon-Ra. That worked out for us. It probably gave Coach Helton a tough time, sorry about that coach."

"That's OK," Helton responded. "I know you'll do it again."

Indeed, the way this season is going, it wouldn't be a surprise to find Slovis and Co. in that all-too-familiar position once more ... or for it to work out in memorable fashion yet again.