SANTA CLARA, Calif. — Who’d have thought a kid who planned to spend his entire life in Tuscaloosa would become the greatest threat to college football’s greatest dynasty? Who’d have believed a teenager could help him topple it?

For the second time in three years, Dabo Swinney’s Clemson juggernaut denied Alabama back-to-back national titles and offered an unshakable case that it is the country’s preeminent program, with 19-year-old true-freshman quarterback Trevor Lawrence leading the Tigers to an unthinkable 44-16 beatdown of Nick Saban’s top-ranked Crimson Tide on Monday night at Levi’s Stadium.

In becoming the first undefeated champion of the playoff era, Clemson (15-0) achieved the greatest record of any national champion since 1897 while stopping Saban from securing a record seventh national championship.

Swinney, expected to lead the Tigers only on an interim basis a decade ago, claimed his second championship with a program that previously hadn’t won one since 1981, joining Saban as the only active head coach with multiple titles.

Handing Alabama its most humiliating moment ever was the Birmingham, Ala., native who grew up worshipping “Bear” Bryant, the walk-on who won a national championship with the Crimson Tide, the assistant coach who raised his family in the shadow of Bryant-Denny Stadium.

“I know 10 years ago, not many people probably saw this coming, but we’re here, and we did it. It’s amazing,” Swinney said. “We’re just little ol’ Clemson. We’re not supposed to be here. We’re not supposed to be the first 15-0 team in history. We’re not supposed to be here, but we are.”

Here Clemson was again, facing a team praised as one for the ages and knocking the long-unquestioned king from the throne once more.

“There was a lot of talk about ‘best ever’ all year long. We were never in that conversation,” Swinney said. “But tonight, there’s no doubt. First 15-0 team.”

Two years ago, Hunter Renfrow gave Clemson its long-awaited title with his final-second touchdown catch. This time, the celebration started before the fourth quarter began.

After watching in awe of Tua Tagovailoa during last year’s title game, Lawrence displayed the poise expected of the Heisman runner-up and became the first true-freshman starting quarterback to lead his team to a title since 1985 (Jamelle Holieway, Oklahoma), throwing for 347 yards and three touchdowns.

Lawrence opened 2-of-7 but quickly settled in and started the countdown to the 2021 draft with one NFL-ready throw after another, dismantling a dynasty defined by defense.

By halftime, the Tigers led 31-16, tying the most first-half points ever allowed by Alabama in Saban’s 12-year tenure. Soon after, the high school kid who watched last year’s game on TV was watching his friends make confetti angels at midfield.

“It was just surreal,” Lawrence said. “Just an unbelievable experience.”

Lawrence’s performance was rivaled only by his defense.

Less than two minutes after kickoff, A.J. Terrell returned an interception 44 yards for a touchdown. Trayvon Mullen picked off Tagovailoa next, ending a second-quarter drive that would have put Alabama back in front.

After holding a brief 16-14 lead, Alabama’s 48-points-per-game offense was held without a point for the final 44 minutes.

“The whole defense came to play,” Mullen said. “We just kept grinding.”

Last year, Alabama recovered from a 13-point halftime deficit against Georgia. This year, the Crimson Tide curled into a ball, as Saban, 67, looked older than retirement age for the first time, badly outclassed by his younger counterpart.

The Tigers were too tough, too well-prepared and too damn confident, understanding they had become the power without a peer.

Even if one dynasty didn’t die, another already may have been born.

“We’re the best team ever,” said defensive lineman Christian Wilkins, whose senior class’ 55 wins rank as the most in the sport’s history. “No one can take that away from us. 15-0.”