PARIS -- Again far from his best, Roger Federer still managed to win at the French Open.
Top-seeded Novak Djokovic had a much easier path.
Federer, the 2009 champion at Roland Garros, was pushed to four sets Friday for the second straight match, this time beating Nicolas Mahut of France 6-3, 4-6, 6-2, 7-5 in the third round.
"I think for bigger guys it's about, if you're able to move them around enough and they have to defend time and time again, this is maybe where you can expose some of their weaknesses potentially," Federer said. "I thought he did well. (I) struggled a little bit, but overall obviously I'm happy I came through."
Federer improved his record number of Grand Slam match victories 235. The 16-time Grand Slam champion is trying to become the first man over 30 years old to win a major title since Andre Agassi in 2003 at the Australian Open.
For Mahut, it was the first time he won a set against Federer in four matches.
"I was believing in it. I was maybe a bit nervous going into that center court, but this went well," Mahut said. "But I'm disappointed, because you always want to do better. Disappointed I didn't win that fourth set."
Djokovic also advanced to the fourth round, extending his Grand Slam winning streak to 24 by beating Nicolas Devilder of France 6-1, 6-2, 6-2 in a match that ended just as the sun was setting.
"Last 15 minutes was very hard," Djokovic said. "It was very important for me to finish the match today. I wouldn't like to come back tomorrow and play a few games."
Next up for Federer is Belgium's David Goffin, who is unbeaten in Grand Slam main-draw matches. (OK, so the kid's only 3-0, but still.)
Before Federer can take on Djokovic or Rafael Nadal, he'll need to defeat Goffin, the first "lucky loser" -- a player beaten in qualifying who sneaks into the field via someone's withdrawal -- to reach the fourth round at any Grand Slam tournament in 17 years, and only the seventh to make it that far.
"Now I'm playing against Roger," the 109th-ranked Goffin said after beating Lukasz Kubot of Poland 7-6 (4), 7-5, 6-1 on Friday, "and I can't believe it."
A fresh-faced 21-year-old whose voice was barely a whisper and whose hands fidgeted during an extended interview session with reporters, the slender, 5-foot-11 Goffin matter-of-factly discussed displaying photos and posters of 16-time Grand Slam champion Federer in his bedroom as a child.
"Since I was little, I've watched Roger play on TV. To me, he plays almost perfect tennis. His technique is perfect. I also like him at the human level; he's a very good person on and off the court," said Goffin, who was able to make his Grand Slam debut because France's Gael Monfils pulled out with a knee injury. "I expect a very tough match on Sunday, of course. I don't really know how I'll prepare for it, but I'll try to have fun."
Informed that his next opponent is an unabashed fan, Federer grinned and replied, "Not the first time it happens."
Probably so. After all, the 30-year-old Federer has been winning major titles since 2003, when Goffin was 12, and winning Grand Slam matches since 2000.
Federer happened to catch a bit of Goffin's second-round matchup against Arnaud Clement, the 2001 Australian Open runner-up who said this would be his final French Open.
The condensed scouting report?
"Nice game. Smooth ball-striker. And talented, obviously," Federer said. "Otherwise, he wouldn't be coming that far in this tournament."
That match against Clement went five sets, as did Goffin's first-round victory over 23rd-seeded Radek Stepanek -- the only five-setters of his career. Against Kubot at intimate, 1,559-seat Court 7, Goffin was raucously cheered by flag-waving, chorus-singing supporters who made the short trip from Belgium.
"It gave me wings," Goffin said. "I felt as if I was playing at home."
Coincidentally, the last "lucky loser" to make it this far at a major tournament was also Belgian, Dick Norman, who did it at Wimbledon in 1995.
Now comes by far the toughest test of Goffin's young career.
Or, looked at another way, a "bonus," as he put it: the thrill of standing across the net from his favorite player and seeing how he stacks up.
Asked whether he believes he can defeat Federer, Goffin said, "If I say yes, it might sound pretentious. And if I say no, it will look like a lack of ambition. We'll see. I'll prepare like I do for other matches. I'll try to go for my shots and have fun on a big court."
No. 5 Jo-Wilfried Tsonga of France, No. 7 Tomas Berdych of the Czech Republic and No. 9 Juan Martin del Potro of Argentina also won, while No. 11 Gilles Simon lost.
Information from The Associated Press was used in this report.