Utah football already beat USC once. Can the Utes do it again?

It wasn’t just that USC lost a game at the University of Utah on Oct. 15, it was the manner in which the Trojans dropped their only game this season.

Trailing by 14 points three different times in the first half, at Rice-Eccles Stadium, Utah awoke on both sides of the ball after halftime.

The defense did not stop Caleb Williams, but it significantly slowed down the star sophomore quarterback. The offense scored touchdowns on five of its final six possessions, capped by Cam Rising’s 1-yard plunge on fourth-and-goal and ensuing two-point conversion run with 48 seconds left for a 43-42 win.

As the No. 4 Trojans and 11th-ranked Utes prepare to face each other again in Friday night’s Pac-12 championship game (6 p.m., FOX), there is more at stake for both sides than there was six weeks ago. Utah is going to the Rose Bowl with a win, USC likely to the College Football Playoff if the Trojans prevail.

The way first-year USC head coach Lincoln Riley sees it, looking backward six weeks doesn’t do anyone any good.

“This is not a revenge game, that’s not what this is,” Riley told reporters in Los Angeles earlier this week. “We played a really good football game, as did Utah up in Salt Lake. It was an elite college football game that came down to one play here or there. They got us that time, but this is not about that game. This is a new game, a new challenge, a new setting. Teams have evolved, both teams have changed certainly throughout the year. This is about that and obviously the opportunity at hand.”

Whether or not there is something to be gained Friday night from a game that took place six weeks ago is debatable, but the key defensive matchup from that night for Utah stands out enough that it bears watching at Allegiant Stadium in Las Vegas.

Williams ran roughshod on Utah defensive coordinator Morgan Scalley’s defense in the first half on Oct. 15, passing for 229 yards and three touchdowns. He was “limited” in the second half to 9-for-15 passing for 112 yards and two touchdown passes as the high-octane Trojans offense managed just 192 yards of total offense in the second half.

That second half marked a turning point for the defense. After giving up over 500 yards of total offense to UCLA and USC in consecutive weeks, the unit has clamped down, finishing the regular season ranked No. 1 in the Pac-12 and No. 17 nationally in total defense at 317.5 yards per game.

Conversely, Williams finished the regular season ranked fifth nationally in total offense at 338.6 yards per game.

“That was the onset of the defense kind of pivoting and making a reversal, the second half of that game,” Utah head coach Kyle Whittingham said. “We played extremely well in the second half of that USC game and from that point on, we’ve played pretty good defense.”

Whittingham noted that ahead of the first meeting, USC was a “10″ personnel-heavy team, meaning one running back and four receivers, with “11″ personnel being the second group with one running back, one tight end and three receivers. Whittingham believes that has flip-flopped, with USC now offering more “11″ personnel looks.

Riley intimated that he doesn’t expect Utah to make wholesale changes to what got it to this point, but did veer towards the old coaching notion that teams evolve over the course of a season. Guys get hurt, new guys step in, different guys get featured.

What Riley said there fits what Utah has been lately.

Rising injured his left knee in that first meeting, and has worn either a brace or protective sleeve ever since. Dalton Kincaid shredded the Trojans to the tune of 16 catches for 234 yards and a touchdown, but has since dealt with a shoulder injury, and now what appeared to be a lower back issue last week at Colorado. Whittingham said Monday he expects Kincaid to play on Friday.

Clark Phillips III missed the Colorado game, Tavion Thomas is no longer on the team, Ja’Quinden Jackson is coming off the first 100-yard rushing game of his career.

Most of the personnel USC will see on Friday night is the same as Oct. 15, but that doesn’t mean Utah is the same team.

“Advantages are that you know each other and how they’re going to play you most likely,” Williams said. “The things that worked for them, they’ll probably practice them a bit more and get a few more reps of that. Run it a little bit more and then try to throw in some things you haven’t seen against them.

“Disadvantages are you’ve played against them already, they’ve seen things you’re good at and they’re going to practice those, get a lot of reps on those.”