Men’s singles results Haas bt Sock 7-6, 6-2, 7-5Isner bt Harrison 5-7,6-7,6-3,6-1, 8-6Youzhny bt Delbonis 6-3, 6-7, 7-5, 6-4Tipsarevic bt Verdasco 7-6,6-1,3-6,5-7,8-6Nadal bt Kližan 4-6, 6-3, 6-3, 6-3Wawrinka bt Zeballos 6-2, 7-6, 6-4Janowicz bt Haase 6-4, 4-6, 6-4, 6-3Davydenko bt Istomin 6-4, 7-5, 6-2Gasquet bt Przysiezny 6-3, 6-3, 6-0Troicki bt Cilic 7-6, 6-4, 7-5Federer bt Benneteau 6-3, 6-4, 7-5Ferrer bt López 6-1, 7-5, 6-4PARIS. Defending champion Rafa Nadal stuttered for the second time so far at the French Open before moving through to the third round with a 4-6 6-3 6-3 6-3 victory over Slovakia’s Martin Klizan on Friday.The Spaniard, looking for his eighth Roland Garros title, looked ill at ease as fellow left hander Klizan came out swinging and dropped the first set before raising his game enough to claim victory in two hours 44 minutes.In the third round, number two seed Roger Federer eased past France’s Julien Benneteau 6-3 6-4 7-5 to reach the fourth round in awe-inspiring fashion.There was the usual array of running aerial forehands, gravity-defying drop shots and whipped backhands as the former world number one booked a meeting with American Sam Querrey, the 18th seed, or French 15th seed Gilles Simon.Benneteau, the 30th seed, broke in the first game to open a 2-0 lead but 17-times Grand Slam champion Federer kept his cool and turned the situation around in no time.Benneteau, who has been struggling with a groin problem, bowed out on the first match point when he could not retrieve another powerful Federer forehand.Federer left Court Philippe Chatrier on a standing ovation from the Paris crowd."You are so nice to me,” Federer said courtside with a smile. "I’m sorry for Julien, he looked diminished,” he added after a 91-minute tennis masterclass.Benneteau started with an exquisite crosscourt forehand winner and took the first game on Federer’s serve but the Frenchman, who beat the Swiss in Rotterdam this year, could not sustain the pace.At 3-3, Federer upped the tempo, winning 14 points in a row to snatch the opening set and he started the second in convincing style with some jaw-dropping shots.The second game of the second set lasted just 45 seconds and Federer flicked a sublime backhand into Benneteau’s feet to break decisively in the ninth game.Benneteau continued to fight in the third, but Federer, who won the title in Paris in 2009, was simply too good.Thursday’s heavy rain meant Nadal’s match was one of several second-round ties held over and having not played since Monday, and the Spaniard was clearly not firing on all cylinders against Klizan.On Monday he was pushed hard by Daniel Brands and world number 35 Klizan had obviously taken a leaf out of the German’s book with some heavy hitting from the baseline to break the misfiring Spaniard’s serve in the eighth game.Klizan brought up set point with a second serve ace and claimed the opener in 40 minutesNadal surged 4-0 ahead in the second but 23-year-old Klizan remained a threat and recovered one of the breaks of serve.Third seed Nadal took the second set and then moved a break ahead in the third but wobbled at 3-2 when Klizan earned two break points, only to squander his chance to draw level.Klizan’s challenge then faded and Nadal, without looking totally convincing and carelessly dropping serve late in the fourth set, secured a Saturday clash with Italian Fabio Fognini.American marathon man John Isner soothed the memory of his record-breaking loss at last year’s French Open with victory over Ryan Harrison in another five-set epic.A year to the day that he lost to local favourite Paul-Henri Mathieu in a 76-game battle, the most ever played in a men’s match at Roland Garros, Isner held off young gun Harrison to win 5-7 6-7 (7) 6-3 6-1 8-6 in three hours 50 minutes.The 19th seed looked to be on the way out after dropping the opening two sets in a second-round match held over from Thursday but struck back to grind down his 21-year-old rival.After sealing victory, the 28-year-old was bent double after another brutal encounter and clearly relieved after ending a six-match losing sequence in matches going to five sets.Isner, who faces Tommy Haas next, holds the overall all time record for the longest professional match in history when he beat France’s Nicolas Mahut 6-4 3-6 6-7 7-6 70-68 at Wimbledon in 2010. The match lasted 11 hours and five minutes.In a later match on Friday, David Ferrer - the fourth seed - beat fellow Spaniard Feliciano Lopez 6-1 7-5 6-4 in the first match of the third round.