LAS VEGAS — Woody Marks scored on a 13-yard run with 8 seconds left to give No. 23 Southern California a 27-20 victory over No. 13 LSU on Sunday night.

Miller Moss threw for 378 yards and a touchdown and his 20-yard completion to Kyron Hudson and a subsequent targeting penalty on LSU with 18 seconds left set up Marks’ winning score in the season opener for both teams.

Moss outpaced LSU’s Garrett Nussmeier, who completed 29 of 38 passes for 304 yards with two touchdowns and an interception on the final drive. Moss was equally efficient, completing 27 of 36 passes in a battle of QBs biding their time after sitting behind the two most recent Heisman Trophy winners, LSU’s Jayden Daniels and USC’s Caleb Williams.

USC, joining the Big Ten Conference for the first time, signaled the Trojans could be a force to be reckoned with with the win in the teams’ first meeting in 40 years after a disappointing 8-5 last year.

And it came against a Southeastern Conference opponent hoping to show they belong in the College Football Playoff. LSU still has a chance to prove that, but this is the Tigers’ third straight season-opener loss under coach Brian Kelly. LSU also saw its four-game winning streak since last season snapped.

The Tigers accounted for about 60 percent of the crowd, an announced record attendance of 63,969 at Allegiant Stadium, which at times felt like Baton Rouge West. There was some star power, too, with LSU greats Shaquille O’Neal and Daniels, with his Heisman Trophy in tow. Former USC Heisman winners Marcus Allen and Matt Leinart were also in attendance.

Two great catches defined the first half.

Hudson leaped high and back, extending his right hand to somehow bring the ball to his other hand and into his body for a 24-yard completion to LSU’s 19-yard line. The play stood after video review, and it set up a 2-yard touchdown run by Marks to put the Trojans up 7-0 with four minutes left in the second quarter.

LSU’s Kyren Lacy responded with an acrobatic catch, spinning the ball and just getting his right foot downfield for a 19-yard touchdown to tie the score midway through the period.

Both teams also missed opportunities — the Tigers were denied on downs after a drive to the USC 3, and Trojans kicker Michael Lantz missed a 29-yard field goal to the right as the first-half clock expired. The Trojans could have had an extra 30-40 seconds on that final possession, but coach Lincoln Riley elected not to call a timeout before LSU tied the game on a 45-yard field goal by Damian Ramos with 1:08 left.

The game was back-and-forth, with the Trojans taking a 20-17 lead with 5:44 left in regulation when Moss found Ja’Kobi Lane for a 28-yard touchdown. Ramos’ 31-yard field goal tied the game but left 1:47 on the clock.

It took too long, as Moss led the Trojans on an eight-play, 75-yard drive to win.