LAS VEGAS – Have you ever been to a good Las Vegas show? The singing, the dancing and the theatrics. The smoke, the lights and the smells.

We saw one on Sunday night, not in a dingy casino ballroom or a dark hotel lobby, but in a football palace built just off Las Vegas Boulevard. There was plenty of smoke (pregame fireworks kept the haze lingering for three quarters). There were main characters and main actors (Heisman Trophy backup quarterbacks Miller Moss and Garrett Nussmeier). There was even dancing (an LSU player was cautioned for a hip-swinging dance in the second quarter).

Singing, shouting, and swaying along? That was there too, two boisterous fan bases, two of college football’s biggest brands, colliding in front of them.

It had everything, right up to a sensational final act – a game-ending drive, a heroic catch and a breathtaking run that led to the winning touchdown.

USC and LSU delivered a playoff-worthy, championship-atmosphere performance to an audience of millions on a holiday weekend Sunday night – a thrilling, heart-pounding Vegas performance that Wayne Newton himself would be proud to support.

The score – USC 27, LSU 20 – doesn’t do justice to the beauty of it all, the intense moments, the outstanding play by the quarterback, the brief lapses in defense and the waves of hilarious momentum changes.

And now we’re left with no choice but to dissect the show and review — or overreact — to a Week 1 game between two teams that, let’s be honest, we don’t really know much about.

Can USC now seriously compete in his big, bad new league?

Can LSU rebound and make the 12-team playoffs?

What we saw Sunday night was a Trojans defense revamped and strengthened by a new coordinator, one that tackled better than any Lincoln Riley defense in his eight years as head coach (the unit held LSU to two crucial fourth-quarter drives). We saw a quarterback, Moss, who shined on the biggest stage after waiting three years for his chance (he completed 75 percent of his passes and rushed for 378 yards).

We saw one receiver, Kyron Hudson, make two of the best catches you’ll ever see: a one-handed, acrobatic catch in the third quarter and a game-winning reception in the fourth, when he caught the ball from Moss on USC’s final touchdown march despite a hit (and a well-aimed hit) from an LSU defender.

Perhaps most surprising was a tackle by the USC defense, yes, a tackle. The Trojans stopped the run (aside from a 39-yard run, LSU had only 78 yards of rushing power) and created a goal-line hold in the first quarter (LSU failed on a fourth-and-goal attempt from the 3).

These superlatives are what made their coach happiest. Riley seemed almost surprised by all of this, certainly impressed by a unit that was ranked 119th nationally a year ago.

We did that? How? Are you sure?

Riley made one of the most talked about decisions of the offseason when he fired coordinator Alex Grinch and hired D’Anton Lynn from UCLA, one of the most touted young defensive minds in the game. A new coach. A new scheme. New players. A new mentality.

“I was proud of how hard and well we played and how much we trusted and didn’t panic. We kept fighting,” Riley said. The defense had a “vibe,” he said – a confidence. “It was so cool to see in that moment and in that arena how much we trusted (the new system).”

The overreactions are obvious:

• Moss, sharp and crisp, composed and quiet, is Riley’s latest contender for the Heisman Trophy.

• USC’s physical, aggressive and clever defense is back in championship form.

• Riley, the $10 million man in his third season, will finally bring Los Angeles a championship.

On the other hand, the other $10 million man, Brian Kelly, was “furious,” he told reporters afterward, especially with an offense that failed to turn a one-point game into a two-point game in the second half. The Tigers had that chance twice, leading 17-13, with possession and momentum on their side.

They lost a yard on a third-and-one attempt that was stopped by Lynn’s repositioned defense. They gained 3 yards on another drive when they needed 6, which was again stopped by Lynn’s quick-tackling defenders just short of the first-down line.

They wasted a 304-yard rush by new starter Nussmeier while the old starter, Heisman winner Jayden Daniels, watched from the sidelines. In the stands, those rowdy Louisianans streamed toward the exits, into the dry Vegas heat, and eventually headed home, annoyed and (probably) hungover.

These are the games that make or break you. They get coaches fired and new ones hired, they enliven the fan base, they inspire it and they drain it of passion.

“It was a playoff game,” said USC athletic director Jen Cohen.

And that’s certainly how it felt: two giants of the sport from football’s two most powerful leagues, their respective commissioners watching from this football palace while the bright lights of the Strip streamed in, illuminating another magical Las Vegas show.

One with a new twist.

“Pretty good Big Ten football today,” Riley smiled.