Novak Djokovic went from a big deficit to his best tennis at the French Open on Monday, erasing a two-set hole and grabbing 13 games in a row in a dominant display before his opponent stopped playing because of a back problem.

The result officially goes into the books as a retirement by Lorenzo Musetti, a talented 19-year-old from Italy making his Grand Slam debut. The score when he quit showed Djokovic ahead 6-7 (7), 6-7 (2), 6-1, 6-0, 4-0.

It took Djokovic more than two sets and two hours to get going in the right direction at Court Philippe Chatrier, but once he did, it became a one-way journey. That included a 19-point run for him bridging the end of the third set and start of the fourth.

Musetti, so good at the outset with his one-handed backhand and tremendous touch, is hardly used to this best-of-five-set format at the majors and he took a medical timeout after the fourth. The French tennis federation said Musetti's reason for stopping was back pain.

This was the second five-setter of Musetti's career he won his third-rounder that way while Djokovic improved to 34-10 when going the distance.

Djokovic wound up 9 for 9 on his break-point chances and with a 53-30 edge in winners.

How surprising was it just to see Musetti take the opening pair of sets against Djokovic, who is seeking his second French Open championship and 19th Grand Slam trophy overall?

The top-seeded Djokovic never had been beaten at Roland Garros by someone ranked as low as the No. 76 Musetti. Djokovic's only previous loss against a teen at the French Open came back in 2006 against some kid by the name of Rafael Nadal. And Djokovic entered the day 14-0 in the fourth round at the place.

Plus, consider Djokovic's recent form: He was 10-0 in Grand Slam matches in 2021 and hadn't ceded more than four games in any set in Paris let alone an entire set while dropping a total of just 23 games until Monday.

Eventually, he earned his fifth career comeback from two sets down by limiting his mistakes and making Musetti look like what he is: Someone with plenty of promise but far less experience than Djokovic.

The 34-year-old from Serbia reached his record 15th quarterfinal in Paris and 49th major quarterfinal in all. It will come against another Italian, No. 9 seed Matteo Berrettini, who advanced without needing to swing his racket once Monday.

That's because the man Berrettini was supposed to face in the fourth round, 20-time Grand Slam champion Roger Federer, withdrew in order to let his surgically repaired right knee and the rest of his 39-year-old body rest with an eye on Wimbledon later this month.

In other fourth-round men's action on the top half of the draw, No. 10 seed Diego Schwartzman saved seven set points in the opening set on the way to eliminating Jan-Lennard Struff 7-6 (9), 6-4, 7-5. Schwartzman, a semifinalist at Roland Garros in 2020, next will face 13-time champion Nadal or No. 18 Jannik Sinner who, like Musetti, is an Italian who is 19.

In women's play, 17-year-old American Coco Gauff became the youngest player since 2006 to reach the women's quarterfinals at any Grand Slam tournament by overwhelming No. 25 seed Ons Jabeur 6-3, 6-1 in under an hour.

Gauff now meets Barbora Krejcikova, who reached her first major quarterfinal with a 6-2, 6-0 victory over Sloane Stephens, the 2017 U.S. Open champion and 2018 French Open runner-up.

Maria Sakkari, who is seeded 17th, beat No. 4 Sofia Kenin, last year's runner-up, 6-1, 6-3. Sakkari's quarterfinal opponent will be 2020 champion Iga Swiatek or Marta Kostyuk.

On an afternoon that began with the sun shining, before clouds intervened, Djokovic's two-handed backhand, his best shot, was off. Way off.

By the second game of the third set, he already had accumulated two dozen unforced errors off that wing alone.

And while Djokovic is normally adept at tiebreakers he made no errors at all in the three tiebreakers of his 2019 Wimbledon final win against Federer Musetti was on-target and so good in those that high-pressure, high-stakes environment. And while Djokovic is normally adept at tiebreakers he made no errors at all in the three tiebreakers of his 2019 Wimbledon final win against Federer Musetti was on-target and so good in those that high-pressure, high-stakes environment. Musetti is now 10-0 in tour-level tiebreakers for his nascent career.

After that, though, Djokovic took over.