"At the start of my career, clay was not my favourite surface," said Federer. "I got my best results in indoor courts or hard courts, so people thought at that time that I was only a fast-court player. But that's not the case, so I'm very happy with this record, and I'm enjoying it."
Fourth seed and 2009 champion Federer extended his record to 5-0 against No. 31 seed Dmitry Tursunov with a 7-5, 6-7(7), 6-2, 6-4 victory in three hours and seven minutes. He is now three match wins shy of 200 clay-court victories (197-60 overall).
Tursunov saved three set points from 0/40 at 5-6 in the second set, before going on to seal the tie-break. He led 4/1 in the tie-break and missed a backhand down the line at 6/5. Federer did not convert a set point opportunity at 7/6, before Tursunov levelled at one-set all at 8/7 with a forehand winner.
"It was tough to lose the second set but nice to win the match," said 32-year-old Federer, who is contesting his 58th straight Grand Slam.
"It was not a straightforward win. I knew Dmitry would try different things, take big cuts at the ball but I am pleased to have played solid."
Tursunov called it a "fairly even battle" prior to suffering a groin injury after the changeover of the second set. "Good for him that he was able to figure out what bothers me and kind of build his game plan around that," he said. "He's a tough player to play against when you're healthy, so definitely makes thing a little bit tougher."
"Clearly he has to be confident after winning a tournament last week and now backing it up again here this week and cruising through, really," said Federer. "I'm aware of the challenge ahead of me, and difficult match I think because I have had some tough matches with him in the past."