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 number one Sinner 4-6, 6-7 (4/7), 6-4, 7-6 (7/3), 7-6 (10/2) to clinch his fifth Grand Slam title after five hours and 29 minutes.

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

Alcaraz pulled off his first ever comeback from two sets down to stun Sinner in the longest Roland Garros final in history. It easily eclipsed the 1982 final in Paris when Mats Wilander triumphed in four sets over Guillermo Vilas in 4hr 42min.

Alcaraz becomes the third youngest man to win five Grand Slams -- after Bjorn Borg and compatriot Rafael Nadal -- following an incredible duel between the two stars of a new generation.

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.

He 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 8-5 overall having also beaten Sinner to win in Rome, where the Italian returned to competition after a three-month doping ban.