PARIS: Novak Djokovic battled back from two sets down to reach the French Open quarter-finals for the 15th time on Monday. World number one Djokovic stayed on course to become the first man in over 50 years to win all four Slams twice after surviving a rousing challenge from 19-year-old Lorenzo Musetti.

The Italian teenager, ranked 76 and making his Grand Slam debut, was poised to condemn Djokovic to his earliest exit in Paris in 12 years when he captured the first two sets, 6-7 (7-9), 6-7 (2-7).

But Djokovic levelled by taking the next two sets, 6-1, 6-0 before Musetti, who had taken a medical time-out, retired at 4-0 down in the decider suffering from a stomach injury.

It was the fifth time in his Grand Slam career that the 34-year-old Djokovic has come back from two sets down to win.

Djokovic, the 2016 champion and chasing a 19th major, reeled off 53 of the last 61 points against the weary Italian as he made a quarter-final at the majors for the 49th time.