Novak Djokovic on Monday became the first man to reach the French Open quarter-finals for 10 successive seasons while Kei Nishikori set-up the toughest challenge on a clay court – facing Rafael Nadal.

Top seed and world No 1 Djokovic continued his bid to hold all four Grand Slam titles simultaneously for the second time by thrashing Germany’s Jan-Lennard Struff 6-3, 6-2, 6-2.

The 32-year-old will now face either ninth-seeded fifth seed Alexander Zverev in what will be his 13th appearance overall in the quarter-finals in Paris.

Alexander Zverev reached his second successive Roland Garros quarter-final with a 3-6, 6-2, 6-2, 7-6 (7/5) win over Italy’s Fabio Fognini.

Last year he achieved his best run at the Slams, making the quarter-finals where he was defeated by eventual runner-up Dominic Thiem.

Karen Khachanov reached his first Grand Slam quarter-final when he defeated Juan Martin del Potro 7-5, 6-3, 3-6, 6-3 at Roland Garros.

Tenth seed Khachanov is the first Russian to reach the last eight in Paris since Mikhail Youzhny in 2010. The 23-year-old will face Austrian fourth seed Dominic Thiem, the runner-up to Rafael Nadal in the 2018 final, for a place in the semi-finals.

“It was the best match ever for me at a Grand Slam,” said Khachanov who seems to like the French capital having won the Paris Masters in the east of the city last year. “Let’s go for more.”

Khachanov fired 57 winners past the two-time Roland Garros semi-finalist Del Potro with victory assuring the Russian of a first ever spot in the world top 10.

Fourth seed Dominic Thiem cruised past the dangerous Gael Monfils in straight sets to reach his fourth successive French Open quarter-final. Last year’s runner-up won 6-4, 6-4, 6-2 on a packed Court Philippe Chatrier.

“It was tricky with the rain, but that’s Paris,” said Djokovic, the 2016 champion after playing in drizzly conditions. “I’m really confident with my serve. I hope it continues like that.”

Only Australian great Rod Laver has held all four Majors at the same time twice before, after his calendar Grand Slams in 1962 and 1969.

“Fabio is playing the best tennis of his life,” said Zverev of the 32-year-old Italian who won his first Masters title on the clay of Monte Carlo in the run-up to Paris. “So I am happy to get through this and into another quarter-final here.”

Zverev is 2-2 against Djokovic in his career but won their only meeting on clay in the Italian Open final in 2017 in straight sets. Fognini, the ninth seed, hit 53 unforced errors as his game fell to pieces after a promising opening set.

Earlier, in a mach continuing from Sunday, Japanese seventh seed Nishikori came back from 1-4 and 3-5 down in the final set to beat Benoit Paire of France and set-up a Roland Garros quarter-final clash against Nadal.

Nishikori won 6-2, 6-7 (8/10), 6-2, 6-7 (8/10), 7-5 in a shade under four hours to reach his third last-eight match at the French Open.

“He almost had it today,” said Nishikori who had led two sets to one when the last-16 tie was suspended on Sunday.

“He served for the match at 5-3 but I just tried to fight and play one point at a time.”

The 29-year-old Japanese could have wrapped it up in the fourth set when he had two match points but squandered both, the second on a double fault.

Paire, the world No 38 who was trying to make the quarter-final of a Slam for the first time, was eventually undone by 15 double faults and 79 unforced errors.

Nishikori has only defeated 11-time French Open champion Nadal twice in 12 meetings with both of those wins coming on hard court.

The Spaniard, celebrating his 33rd birthday on Monday, has won all four of their meetings on clay.

“It’s going to be a tough match, he’s the greatest ever clay court player,” said Nishikori.