Melbourne:In a classic match worthy of a final, fifth-seeded Andy Roddick outlasted Marat Safin 7-6 (2), 2-6, 6-4, 7-6 (2) on Friday to reach the fourth round of the Australian Open. Safin, the 2005 champion and former world No 1, was seeded only 26th as he comes back from a knee injury that kept him from defending his title last year. That meant one of the highly ranked players would have to face him early in the two-week tournament. No 6 Roddick drew the unenviable task and showed his confidence is high again after a malaise that dropped him out of the top 10 last year before he convinced Jimmy Connors to coach him. "The one guy you don't want to play in the third round is probably him," Roddick said. "There wasn't a whole lot between us, to be honest. I just tried to tough him out. He's one of the best in the world, so I definitely had to pick up my game in the third and fourth sets. Anything less than that and I would probably would be going home." Serena wins Serena Williams, also plagued by a bad knee last year and unseeded after winning here in 2005, rallied after No 5 Nadia Petrova served for the match at 6-1, 5-3, showing that she still has superior skills and a strong will to win. Top-ranked Roger Federer had an easier time against 25th-seeded Mikhail Youzhny, beating last year's US Open semifinalist 6-3, 6-3, 7-6 (5). Second-seeded Amelie Mauresmo, the defending women's champion, beat Eva Birnerova and next plays Lucie Safarova, who advanced when Anastasiya Yakimova retired with a back injury. Other women's winners were No 3 Svetlana Kuznetsova, No 7 Elena Dementieva, No 10 Nicole Vaidisova and No 16 Shahar Peer. Express serves For more than three hours, Roddick and Safin exchanged 210 kph-plus serves, stinging groundstrokes, crisp volleys and deft drops, leaving the packed stadium enthralled and applauding every point. Both players were dripping sweat on a still, muggy night that had people in the crowd fanning themselves. The roof had to be closed due to a light rain, and Safin complained bitterly that the court hadn't been dried up enough when play resumed, earning a warning for an audible obscenity. The mercurial Safin later said he was unhappy wet patches remained outside the doubles lines. "It was a joke. It was really, really pathetic," Safin said. "Why I have to put my health in doubt? If I slip and if I get injured and if something happens..." Roddick wasn't sure the controversy affected Safin's play. "With Marat, you know he's going to kind of go on the emotional roller coaster a little bit, but I don't know if that hurts him often," said Roddick, who now faces No. 9 Mario Ancic. "I was just feeling like I should be even keel out there tonight. There was enough emotion in the air." Both players also demonstrated sharp eyes, using the new challenge system to overturn a number of calls, including four in two games of the third set. With Connors watching from courtside after flying in following the death of his mother, Roddick showed his new aggressiveness, charging the net after good serves and short balls from Safin, though he did get a bit more tentative as the match wore on and he was passed a number of times. Safin left everything on the court, including a bit of skin. He fell flat and scraped the fingers on his right hand, and had to have treatment for a bloodied pinkie. Serenaâ€™s dubious stat Williams' 1-6, 7-5, 6-3 victory over Petrova was impressive for a woman who dropped out of the top 100 for the first time since 1997 before climbing back to 95th in the year-end rankings. She was shocked to hear she had just beaten a top 10 player for the first time since she downed Mauresmo in the final here two years ago for her seventh Grand Slam title. "Has it been that long? That's a terrible stat," Williams said, shaking her head in disbelief. Petrova has never reached the final of a major, but she raced through the first set and was serving for the match at 5-3 in the second. Then Williams found another gear. "I really had no other option than for my game to go up," Williams said. "I was down 3-5 and on the verge of being out of the tournament, and I obviously didn't want that to happen. I told myself just to stay in there and do what I had been practicing and it'll come together sooner or later. "I think the more pressure I get, the tougher I get." Some have questioned Williams' fitness. There were no questions after outlasting Petrova. "I wasn't tired at all. I'm still not tired. I feel like going to run a marathon," Williams said, laughing. Williams will face No. 11 Jelena Jankovic - a 6-3, 6-4 winner over Victoria Azarenka - on Sunday. Federer, bidding for a 10th major, extended his winning streak to 32 matches - and 10 straight at Melbourne Park. He next faces 14th-seeded Novak Djokovic, who beat Thailand's Danai Udomchoke. Mardy Fish advanced when veteran Wayne Arthurs retired while trailing 3-0 in the first. Also winning were No 7 Tommy Robredo and No. 16 David Ferrer. No. 18 Richard Gasquet beat Gael Monfils 6-0, 4-6, 7-5, 6-3 in a match between two former world No 1 juniors from France.