Top-seeded Novak Djokovic became the first man to reach 10 consecutive French Open quarterfinals on Monday, posting a 6-3, 6-2, 6-2 win against Germany's Jan-Lennard Struff.
It's the 44th time the 32-year-old Serbian star has reached the final eight of a Grand Slam tournament. He broke Struff five times, saved the only break point he faced and committed only 13 unforced errors in the one-hour, 33-minute match.
"I don't mind cruising along, to be honest," Djokovic said.
"I have played plenty of tight matches in my career that I can rely on that experience. I think it's good to be tested from that perspective, but at the same time, it's also good to cruise along and conserve the energy for what's coming up."
The world No. 1 hasn't dropped a set this year at Roland Garros as he enters a quarterfinal clash with fifth-seeded German Alexander Zverev. They have split four head-to-head matches, with the 22-year-old Zverev winning the only previous encounter on clay in 2017 in Rome.
Zverev came from behind in his fourth-round match, beating No. 9 seed Fabio Fognini of Italy 3-6, 6-2, 6-2, 7-6 (5).
In a match that was interrupted by darkness Sunday night, Kei Nishikori survived a slugfest against home favorite Benoit Paire. The Japanese No. 7 seed moved on to the quarterfinals in Paris for the first time with a 6-2, 6-7 (8), 6-2, 6-7 (8), 7-5 victory.
"I'm just happy to win today," said Nishikori, who squandered two match points during the fourth set tiebreak.
Nishikori improved his remarkable career record in deciding sets to 132-45, including 23-6 in five-set matches and 6-1 at the French Open.
Up next for Nishikori is 11-time champion Rafael Nadal. The second-seeded Spaniard leads their head-to-head series 10-2, including 3-0 on clay.
Another Frenchman's run ended when No. 4 seed Dominic Thiem of Austria eliminated No. 14 seed Gael Monfils 6-4, 6-4, 6-2. Thiem had 27 winners and 14 unforced errors, compared to 25 winners and 35 errors for Monfils.
Thiem, who has reached at least the semifinals at Roland Garros in each of the past three years, will face No. 10 Karen Khachanov of Russia in the quarterfinals. Khachanov advanced by defeating No. 8 seed Juan Martin del Potro of Argentina 7-5, 6-3, 3-6, 6-3.
Defending champion Simona Halep abruptly halted Polish teenager Iga Swiatek's French Open run with a decisive 6-1, 6-0 victory in fourth-round action Monday in Paris.
The third-seeded Romanian converted 7 of 10 break chances, fired 17 winners and made only five unforced errors during the 45-minute match.
Halep extended her winning streak at Roland Garros to 12 matches and made the quarterfinals for the third consecutive year.
Swiatek, who celebrated her 18th birthday on Friday, was playing in the second week of a Grand Slam event for the first time. She committed 19 unforced errors and won only five of her 19 first-service points.
Halep will face an even younger opponent in the final eight in 17-year-old American Amanda Anisimova, a 6-3, 6-0 winner against Spanish qualifier Aliona Bolsova.
Anisimova struck 33 winners and joined 19-year-old Czech Marketa Vondrousova as the second teen to reach the quarterfinals.
No. 14 seed Madison Keys cruised into the quarterfinals with a 6-2, 6-4 win over Katerina Siniakova of the Czech Republic in 78 minutes.
Keys capitalized on five of her six break chances, which made all the difference during a balanced effort that saw her finish with 26 winners and 26 unforced errors. Siniakova, who upset No. 1 Naomi Osaka in the third round, managed only 10 winners against Keys.
"It's always a special and stressful experience every single time," Keys said of reaching the quarterfinals in four of the past six Grand Slam events. "I'm happy that I've gotten through to fourth rounds and quarterfinals now a couple times, but it never, never feels routine."
Up next for Keys is No. 8 seed Ashleigh Barty of Australia, who defeated Sofia Kenin 6-3, 3-6, 6-0.
"It's going to be a tough one," Keys said of facing Barty. "I didn't get to see how she played today, but I feel like clay actually suits her game really well with her kick serve and slice and all that. I'm going to have to have a game plan set to be ready for her."
Barty, reaching the quarterfinals at Roland Garros for the first time, is the only woman to make the final eight in each of the year's first two majors.
Barty won 76 percent of points on her first serve and fired 11 aces against Kenin, including three in her first service game of the match. Kenin, coming off an upset of Serena Williams, had more winners (28-25), but was undone by 29 unforced errors to Barty's 17.