Andy Murray has acknowledged that he will have to be on top of his game if he is to continue his fine clay-court form when taking on David Ferrer.
The Scotsman edged out home favourite Jeremy Chardy 6-4 3-6 6-3 6-2 at Roland Garros this afternoon to secure a place in the last eight of the French Open.
It is a 17th-consecutive Grand Slam quarter-final appearance for Murray, who also has an unblemished record on clay this season, but he admits that he now faces a tough test against Ferrer.
"It gets tougher every match," he is quoted as saying by BBC Sport. "I've got Ferrer next and he has beaten me at the French Open before so I am going to have to play fantastic tennis to go through."
Ferrer eased past Marin Cilic in his fourth-round clash to progress through in Paris.