GLENDALE, Ariz. — Alabama needed all its power and speed Monday night. When that couldn’t do it, it was up to one gutsy trick to help win the fourth title of the Nick Saban dynasty.

It needed all its talent and steely resolve against undefeated Clemson.

Derrick Henry, O.J. Howard, and Kenyan Drake hit No. 1 Clemson with long touchdowns, and No. 2 Ala­bama outlasted the dynamic play of Deshaun Watson to win the College Football Playoff championship, 45-40, on Monday night.

The Crimson Tide won its three previous championship game appearances in runaway fashion. This one finally broke open on perhaps the boldest call of Saban’s career.

With 10:34 left in the fourth quarter and Alabama (14-1) having just tied the game at 24, Saban took a gamble to try to keep the ball away from Watson. He called for an onside kick called Pop Kick from Adam Griffith that Marlon Humphrey caught over his shoulder at midfield.

Tide turned.

‘‘It was tough. It really was,’’ said Saban, who now has more national titles than every other coach except for Bear Bryant, the man who won six and made Alabama synonymous with college football greatness.

‘‘I made the decision to do it because the score was [tied] and we were tired on defense and weren’t doing a great job of getting them stopped and felt like if we didn’t do something or take a chance to change the momentum of the game that we wouldn’t have a chance to win,’’ Saban said.

Moments later, Alabama took back the lead for good. For the second time, Clemson (14-1) lost track of the tight end Howard in coverage and Jake Coker hit him in stride deep for a 51-yard touchdown to make it 31-24 with 9:45 left.

Clemson and Watson proved to be every bit Alabama’s equal. The Tigers just kept coming.

Watson led Clemson to a field goal to make it 31-27, before another Alabama big play. Drake broke free and streaked down the sideline for a 95-yard kickoff return touchdown, diving the last 5 yards to the pylon.

Watson threw his third touchdown pass to make it 38-33 with 4:40 left, and then Alabama went back to its workhorse Heisman Trophy winner. Henry plunged into the end zone for his third touchdown of the game to make it 45-33 with 1:07 left.

‘‘We stand toe-to-toe with everybody in the country,’’ Clemson coach Dabo Swinney said. ‘‘This program doesn’t take a back seat to anybody.’’

Watson threw another touchdown pass to cap a wild 40-point fourth quarter, but would not get another chance. Clemson’s onside kick went out of bounds. Coker took a knee and Alabama was back on top.

After a loss to Ole Miss in mid-September, there were doubters. Saban used them to fuel his team.

‘‘There weren’t many people earlier in the year who thought they could do it,’’ he said.

The Crimson Tide became the second team in college football’s poll era, dating back to 1936, to win four titles in seven seasons. Alabama joins Notre Dame, which won four titles from 1943-49, but those Fighting Irish never even played in bowl games, nevertheless two playoff games.

For Saban, it is his fifth national championship — four in his nine seasons at Alabama.

Watson gave the Tide all it could handle, throwing for 405 yards and four touchdowns, and conjured up memories of Vince Young’s miraculous performance for Texas in the 2006 Rose Bowl that derailed Southern California’s dynasty.

The sophomore, who finished third in the Heisman Trophy voting, had 478 total yards against a loaded Tide defense and bested Young’s 467 yards against the Trojans.

But Watson couldn’t finish the job the way Young did in Pasadena and win the national title.

‘‘All the stats don’t really matter to me,’’ Watson said. ‘‘I just wanted to get the win and do something that we haven’t done in 34 years.’’

Instead, Saban and the Tide raised another trophy.

The Tide hit Clemson early with Henry, who scored the game’s first touchdown on a 50-yard burst through the middle. He finished with 158 yards on 36 carries. Howard was the offensive player of the game with five catches for 208 yards, including a 63-yarder that set up Alabama’s final score.

After Watson and walk-on Hunter Renfrow hooked up for two touchdowns to give Clemson a 14-7 lead at the end of the first quarter, Henry tied it up with a 1-yard plunge.

Trying to become the first FBS team to go 15-0, Clemson did not crumble under the force of Alabama’s might.

But all those five-star recruits and future NFL players that dot the Alabama roster showed they also have plenty of resiliency and toughness. And Saban, the quintessential CEO coach, showed he had a little riverboat gambler in him.

That onside kicked stunned the stadium and Clemson, and brought a big grin to the face of the country’s most serious coach.

The Tide will send another batch of players to the NFL this year, as Saban always does. There is another wave ready to roll.

‘‘I think as long as he’s in Alabama,’’ Coker said, ‘‘Alabama is going to be up at the top.’’