Trevor Lawrence led Clemson with 327 yards and three touchdowns passing. (Tim Warner/Getty Images)

The little slice of time lasted just 238 seconds from a season that began in August and now will extend into January. In that space, Clemson’s football team wedged 12 plays that covered 165 yards. The Tigers showed everything that football coaches spend hours in film rooms and practice ­sessions trying to mine from their players: precision, athleticism, discipline, ­attention to detail. Add to that something more: They were ruthless.

“Just wanting to score,” quarterback Trevor Lawrence said, “every time we get the ball.”

In those 238 seconds, Clemson closed out Notre Dame in the Cotton Bowl, which served as the first College Football Playoff semifinal. There was the foundation of a 30-3 mauling of the Fighting Irish that was complete, thorough, unarguable. Yes, that timespan covered just Clemson’s closing drives of the first half, and sure, the huge blocks of Fighting Irish fans who filled more than half the stadium could have discussed, at halftime, ways to rally. Watch both marching bands go through their routines, have a beverage, and you could maybe figure out a way for the Irish to come back.

But not if you were being real and assessing why Clemson is in the playoff for the fourth straight year. Of Coach Dabo Swinney’s pregame talk, sophomore wide receiver Tee Higgins said: “We’re not playing Notre Dame. We’re playing Clemson. We don’t want to allow Clemson to beat Clemson.”

That’s the standard now. The program’s only peer nationally is Alabama, and that’s just who the Tigers will face for the title a week from Monday in Santa Clara, Calif., the fourth straight year those two programs will play. There are big-picture reasons why that will happen. “Just the culture and the people we have at Clemson,” defensive tackle Christian Wilkins said.

But those 238 seconds — it’s worth reliving them because they represent what the Tigers have become and what they can be at any moment. They were, on Saturday, two drives that transformed a competitive-if-unattractive contest into a beatdown. They show the potential that’s possible against any opponent — including Alabama, which Clemson lost to at the end of the 2015 season, beat to close 2016 and lost to in last year’s semifinals.

What Clemson has is explosiveness and depth at every position, a claim Notre Dame cannot quite make. Where to start? Perhaps with Lawrence — who, it’s worth reminding yourself when you consider what just played out, is a true freshman who just turned 19.

“I never see Trevor nervous,” said another freshman, wide receiver Justyn Ross. “I don’t know how he does it.”

Lawrence’s work on the day: 27 for 39 for 327 yards and three touchdowns. But his work on those two drives is what buckled Notre Dame. With the Irish facing a manageable 9-3 deficit, Lawrence got the ball with just under five minutes remaining in the half and 85 yards to go for a touchdown. By the time the Irish figured out what was happening, Lawrence had dissected a secondary that was without key cornerback Julian Love — out temporarily with an injury — and turned a third-and-14 trouble spot into a 42-yard touchdown pass to Ross.

In that exchange is a key difference between these programs. Clemson endured the absence of standout defensive tackle Dexter Lawrence, suspended after a positive test for ostarine, a banned muscle-growth supplement. The Tigers’ response: Get the next wide body from the depth chart and hold Notre Dame to 248 yards.

The Irish couldn’t overcome Love’s head injury for even a few series. Those 238 seconds spanned the time it took Love to pass Notre Dame’s concussion protocol. He returned in the second half. By then, it was too late.

“We have to be good enough to overcome the loss of one really good player,” Notre Dame Coach Brian Kelly said.

The Irish couldn’t. And Clemson keeps coming with more really good players.

Take Ross. Three Tigers caught more balls than he did this season. But he is — hide your eyes, fans of opposing ACC teams — another true freshman. More than that: He’s a true freshman from Alabama, a true measure of how deep and enduring Clemson’s pull has become. More than that, even: He caught Lawrence’s first touchdown pass — a 52-yarder — and then the beautiful ball Lawrence delivered on a seam route for those 42 yards and a 16-3 lead. Those two players — who were in high school last year — connected six times for 148 yards.

“Every ball he throws is perfect,” Ross said of Lawrence. “You have to try to drop his ball.”

That Lawrence-to-Ross strike would have been enough for the Tigers to establish momentum. But under Swinney, Clemson has developed such an alpha personality that if the door’s open a crack, the Tigers will hop in a bulldozer and barrel through. Their average margin of victory this season was nearly 32 points, and that didn’t happen because Swinney and his staff eased into halftimes by taking a knee.

Rather, when Notre Dame failed to convert on its next possession, Clemson called a timeout. Lawrence got the ball back at his team’s 20 with 48 seconds left. One game-changer: a 32-yard completion to veteran Hunter Renfrow, whose eligibility may someday actually expire. That killer became worse for Notre Dame when senior defensive tackle Jerry Tillery obviously and stupidly roughed Lawrence.

All that was left to suck the suspense from Texas and have the Tigers thinking to next week in California was Lawrence’s final throw of the half. On this one, from 19 yards, he got help from Higgins, who concentrated on a tipped ball and hauled it in as he stumbled out of the back of the end zone.

Another salient fact: Higgins, Clemson’s leading receiver, is a sophomore.

These guys aren’t going away. On those two drives that changed the game, Lawrence completed 7 of 8 throws for 125 yards and the two scores.

“Poise,” Swinney called it. That’s part of it, sure. But Lawrence is now part of what has become a Clemson machine. The Tigers seniors won the 54th game of their careers Saturday. Dexter Lawrence’s suspension didn’t magically take defensive ends Clelin Ferrell and Austin Bryant and defensive tackle Wilkins out of action, too. Sure, Lawrence is a load at 350 pounds. But Albert Huggins, who started in his stead, is a senior who’s hardly a fragile flower at 315 pounds. The Notre Dame offense revolves around back Dexter Williams. His total Saturday: 16 carries, 54 yards. The Tigers, they swallowed him whole.

And so the second half — particularly after Irish quarterback Ian Book threw his only interception of the day, near the end of the third quarter — devolved into a debate that has marred the five years of the College Football Playoff’s existence: Should the committee take the team with the best résumé — and Notre Dame, with a spotless 12-0 record, was worthy — over a team that was playing better ball late in the year.

That team, in this case, would be Georgia — which lost at LSU, mysteriously, and to Alabama in the SEC championship game, understandably. Would the Bulldogs have given Clemson a better game Saturday evening? Possibly. ­Maybe even probably.

But that debate shouldn’t matter much. Look at those 238 seconds. What’s revealed there is what Clemson is: a national power that is now a national program, recruiting whatever players it wants from wherever they’re raised. And every year, it is a threat to win the national championship. Watch the end of the first half Saturday, and try to think otherwise.