PARIS   -  When it comes to the deciding set, count on Kei Nishikori. The Japanese player won his eighth consecutive five-set match on Monday to defeat Benoit Paire 6-2, 6-7 (8), 6-2, 6-7 (8), 7-5 over two days and set up a quarterfinal against defending champion Rafael Nadal at the French Open.

In a match ridden with unforced errors, 15 breaks of serve, but also some beautiful shots, Nishikori prevailed after a nearly four-hour battle. Their fourth-round match had been suspended by darkness on Sunday, with Nishikori leading by two sets to one. Nishikori extended his impressive record in five-set matches to 23-6, including a 6-1 mark at the clay-court Grand Slam. He also holds the best percentage of wins in deciding sets (132-45) — either in best-of-five or best-of-three matches — since the Open Era began in 1968.

In damp conditions, Paire’s all-risk tennis was working when they came back on court. The Frenchman saved two match points in the fourth-set tiebreaker and served for the match at 5-3, but he was finally made to rue his awful mistakes. “He was serving for the match, and I just tried to play one point at a time,” Nishikori said. Paire hit 15 double-faults and 79 unforced errors. “Never easy to finish a match,” Paire said. “It was tough emotionally. I’m very sad to lose this match but glad for what I did this week.”

Nishikori will play in a third quarterfinal in Paris but faces a tall order in the next round. Nadal has won 10 of their 12 previous matches, including all three on clay. Top-ranked Novak Djokovic had an easier time against 45th-ranked Jan-Lennard Struff of Germany, becoming the first man to reach the French Open quarterfinals 10 years in a row with a 6-3, 6-2, 6-2 victory. His quarterfinal opponent will be No. 5 Alexander Zverev or No. 9 Fabio Fognini.

Last year’s runner-up, Dominic Thiem, ended French hopes of Roland Garros glory by ousting Gael Monfils, the last Frenchman remaining in the draw, 6-4, 6-4, 6-2. Monfils had not dropped a set in his three previous matches but could not find an answer to his opponent’s consistency. Thiem produced a superb winner in the third set when, after being dragged to the net, he chased a backhand toward the baseline and fired a winner between his legs. “He was just stronger, he impressed me a lot today,” Monfils said.

In the women’s draw, Sofia Kenin and Katerina Siniakova could not follow up their upsets of Serena Williams and Naomi Osaka. Kenin lost to eighth-seeded Ash Barty 6-3, 3-6, 6-0, while 14th-seeded Madison Keys advanced to the last eight for the second straight year with a 6-2, 6-4 victory over Siniakova. Keys and Barty will face off in the quarterfinals. “It’s going to be a tough one,” said Keys, a semifinalist in Paris last year. “I feel like clay actually suits her game really well with her kick serve and slice.”