For World No. 1 Novak Djokovic, Tuesday was another ho-hum opener at the French Open.

For two men hoping to one day take Djokovic's title of world's best, it was anything but.

Djokovic cruised past Mikael Ymer of Sweden 6-0, 6-2, 6-3 for his 16th straight opening win at Roland Garros. He moved to 60-2 all-time in the first round at a Grand Slam event.

Stefanos Tsitsipas of Greece and Andrey Rublev of Russia, however, each needed to recover from two sets down to move to the second round. The 22-year-olds faced either other Sunday in a three-set final at Hamburg, won by Rublev, before heading to cold and damp Paris.

Tsitsipas, the tournament's No. 5 seed, endured Tuesday to beat Jaume Munar of Spain 4-6, 2-6, 6-1, 6-4, 6-4 in three hours and 12 minutes.

"I don't think I've ever played a match like this before," Tsitsipas said. "The emotions and the nerves at the very beginning were not there, but [I made] slight adjustments and tried to find a way to win, a different way."

Tsitsipas hit 36 of his 54 winners on the day in the final three sets to turn his fortunes around.

"It wasn't working out for me in the beginning. Nothing was working... But I am really proud of myself, the effort I put in and the amount of dedication."

No. 13 seed Rublev outlasted American Sam Querrey 6-7 (5), 6-7 (4), 7-5, 6-4, 6-3 in a match between two big servers.

Querrey landed 29 aces and won 65 percent of his first-serve points; for Rublev, it was 23 aces and 77 first-serve wins. But Rublev was able to capitalize on the mistakes. Querrey double-faulted 11 times and had 62 unforced errors against 80 winners. Rublev struck 64 winners but limited his unforced errors to 20.

It was the first time Rublev rallied from two sets down in his career to win a match.

Other winners on the day were No. 7 Matteo Berrettini of Italy, No. 9 Denis Shapovalov of Canada, No. 10 Roberto Bautista Agut of Spain, No. 18 Grigor Dimitrov of Bulgaria, No. 20 Cristian Garin of Chile and No. 21 Dusan Lajovic of Serbia.