Germany's Daniel Altmaier won the fifth longest ever French Open match as 16-year-old Mirra Andreeva made the Last 32, providing a tantalizing glimpse into the sport's future.

Altmaier saved two match points and then held his nerve on a fifth match point of his own to knock out Italian eighth seed Jannik Sinner 6-7 (0/7), 7-6 (9/7), 1-6, 7-6 (7/4), 7-5 after five hours and 26 minutes of breathless action on Court Suzanne Lenglen.

"I just love the game of tennis," said Altmaier, ranked 79 in the world and who broke down in tears at the end of the marathon.

"I don't know if you can call it a historical match, but it was one to remember. Playing every point you can with the best effort, that's what keeps you in reality."

The longest ever match at Roland Garros remains the six hours and 33 minutes it took Fabrice Santoro to beat fellow Frenchman Arnaud Clement in 2004.

The 24-year-old Altmaier, who made the Last 16 in 2020, twice faced defeat when Sinner was serving for victory in the fourth set.

He battled back to level the tie and broke in game seven of the decider but then failed to serve it out.

He immediately gave himself another chance, though, and this time crept over the line as he secured a surprise win on his fifth match point after a thrilling final game in which he also saved three break points.

Next up is a clash with Bulgaria's Grigor Dimitrov for a place in the Last 16.

"That's sport," Sinner said.

"I'll come back but it's tough to swallow."

Andreeva became just the seventh player under the age of 17 to make the third round in Paris in 30 years — joining the likes of Serena Williams and Martina Hingis — with a 6-1, 6-2 win over Diane Parry of France.

Andreeva, ranked at 143 and making her Grand Slam debut after coming through the qualifiers, will face Coco Gauff in the next round.