Carlos Alcaraz saved three championship points as he produced an astonishing fightback from two sets down to beat Jannik Sinner in a French Open final for the ages on Sunday.

Reigning champion Alcaraz rallied from the brink of defeat to overcome world No. 1 Sinner 4-6, 6-7 (4/7), 6-4, 7-6 (7/3), 7-6 (10/2) after five hours and 29 minutes to clinch his fifth Grand Slam title.

The 22-year-old Spaniard is now unbeaten in five Grand Slam finals after snapping Sinner's 20-match winning run at the majors.

"This was the most exciting match that I've played so far without a doubt," Alcaraz said.

"I think the match had everything."

Alcaraz pulled off his first ever comeback from two sets down in the longest Roland Garros final in history, recovering from 5-3 down in the fourth set when Sinner had three match points.

"Today was all about believing in myself. Never doubted myself today and I tried to go for it," he said.

"Real champions are made in those situations."

Alcaraz is the first man to win a Grand Slam title after saving a match point since Novak Djokovic beat Roger Federer in the 2019 Wimbledon final. The only other man to do it in the Open era was Gaston Gaudio at Roland Garros in 2004.

Sinner fell agonizingly short of a third successive Grand Slam crown after last year's US Open title and back-to-back Australian Open triumphs.

"It's easier to play than talking now," a devastated Sinner said.

"I won't sleep very well tonight but it's okay.”

"We try to delete it somehow and take the positive and keep going. There are no other ways," he added.

"It hurts, but you cannot keep crying."

Sinner suffered his fifth straight loss to Alcaraz in what was their first meeting in a Grand Slam final — and the first championship match at a major between two men born in the 2000s.

Alcaraz leads 8-4 overall having also beaten Sinner in the final in Rome, where the Italian returned to competition in May after a three-month doping ban.

Alcaraz put the pressure on Sinner by carving out three break points to start Saturday's final, but the Italian resisted and soon had a chance of his own.

He couldn't take advantage and found himself having to fend off two more breakpoints at 1-1, producing clutch serves to grind out another tough hold.

Alcaraz's persistence paid off in the fifth game when he broke to nudge 3-2 ahead, only for the Spaniard to immediately hand the lead back.

The unshakeable Sinner threatened to break again at 4-3, with a brief lapse from Alcaraz eventually enabling Sinner to snatch the first set.

Sinner hit the accelerator to start the second set, surging 3-0 in front. After facing seven break points in the opener, he tightened up considerably on serve.