Roger Federer's clash with Monfils is resting on knife edge
Roger Federer will have to come back today to try to seal his place in the French Open quarter-finals after his match against Gael Monfils was suspended for darkness at one set all.
The pair got off to a late start in Paris after rain had earlier delayed play and while Federer clinched the opening set 6-3 in just 29 minutes, Monfils found form in the second to hit back 6-4 and evenly poise the tie.
Federer, who is the second seed at Roland Garros, is looking to beat the Frenchman for the first time in three meetings on clay but Monfils, roared on by the home crowd, will provide a stern test when the duo resume play on Philippe Chatrier.
The winner will play eighth seed Stan Wawrinka in the last eight after the Swiss eased past France's Gilles Simon 6-1 6-4 6-2.
Wawrinka has only dropped one set in his four matches so far and he made light work of Simon, winning in one hour and 51 minutes.
The match of the day came before Federer and Monfils took to the court, as Jo-Wilfried Tsonga knocked out fourth seed Tomas Berdych 6-3 6-2 6-7 (7-5) 6-3.
Tsonga looked on course for a comfortable win when he raced through the opening two sets but he failed to close out when serving for the match at 5-4 in the third.
Berdych clawed one set back but the French world number 15 held his nerve to progress.
"It was not easy because I played really well during three sets," Tsonga said.
"When it was time to finish, I played a little bit differently and because he's a good player, he came back into the match. Then I started to miss a little bit more.
"But I had a good reaction in the fourth and finally I won it. So it's good for me. I'm happy to beat a guy like this, who is one of the best players at the moment."
Tsonga will now face Japan's Kei Nishikori, who cruised past Russian Teymuraz Gabashvili, winning 6-3 6-4 6-2.
It is Nishikori's second consecutive Grand Slam quarter-final after reaching the same stage at the Australian Open, and he has won four out of his five previous meetings against Tsonga.
"He's a very good player," Tsonga said. "He's younger than me. He's got a lot of talent. He's able to do many things on court.
"I had problems playing against him in the past, so for me it's going to be the opportunity to take revenge and try to play my best tennis and try to reach the semis."
Britain's Andy Murray faces France's Jeremy Chardy in the last 16 today.
Murray insists he has no regrets about pulling out of the Italian Open earlier this month after Chardy revealed he was irritated by the Scot's decision to withdraw.
Murray beat Chardy in the Rome second round two weeks ago but, after reaching consecutive finals in Munich and Madrid, the Scot decided to ditch the tournament to conserve energy for Roland Garros.
Chardy admitted he had been a "little bit p*****" by the Scot's withdrawal, adding "if you want to win a Grand Slam, everybody is tired".
The comments add spice to the pair's reunion today but Murray is adamant his decision to pull out in Rome was the correct one.
"At the time it certainly felt like it was," Murray said. "I was extremely tired. I wanted to try to compete as best I could that week but the more time I spent in the event, I realised I felt very tired.
"The evening that I played the match against Chardy, I woke up the next day immediately feeling pretty tired.
"I had a bad practice before my match with (his next opponent) David Goffin. It was a tough decision, but at the time it felt like the right one."