Sydney: French Open champion Rafael Nadal withdrew from his first-round match at the Sydney International on Tuesday with a right groin injury, less than a week away from the Australian Open.Australia's Chris Guccione was leading 6-5 and the set was on serve when the top-seeded Nadal decided, after his second medical time-out, to retire from the match."I will have some treatment on it Wednesday, and will hope to be 100 per cent fit for next week," said Nadal. "The Australian Open is a priority." Nadal was among four retirements at the tournament on Tuesday. Paradorn Srichaphan of Thailand (wrist) also pulled out on the men's side, while in the women's draw former U.S. Open champion and second-seeded Svetlana Kuznetsova (respiratory virus) and No 4 seed Nadia Petrova of Russia (abdominal strain) both quit their matches early.Nadal, second in the world rankings behind Roger Federer, missed last year's Australian Open with a foot injury that kept him off the circuit for four months.At last week's Chennai Open, Nadal lost in the semifinals in straight sets to Belgium's Xavier Malisse amid unconfirmed reports that he was carrying an injury.On Tuesday against Guccione, a hard-serving left-hander, Nadal saved two break points in his first service game and then received his first medical treatment in the seventh game."That's unlucky for Raf at this time of year," said Guccione, commenting on Nadal's injury. "The first I saw of it was when he got the trainer out on court."BlakeaÂÂs easy winEarlier, defending champion James Blake beat fellow American Kevin Kim 6-3, 6-4. Blake needed just 46 minutes and had six aces to overpower Kim in the Australian Open warmup tournament at the former 2000 Olympic complex in western Sydney."I came into last year with no real expectations," Blake said. "It's a very difficult draw, a lot of the top players, everyone looking to peak around this time."It's not going to be easy, but I would love to have as much success as I had here last year and then maybe take it to Melbourne with even more confidence and hopefully go a little further."Qualifier Ivo Minar of the Czech Republic advanced to the second round when Paradorn had to retire in the second set. Minar was ahead 6-2, 3-0.Top-seeded Amelie Mauresmo, who received a first-round bye, beat French compatriot Tatiana Golovin 6-7 (4), 7-5, 6-1 to move into the women's quarterfinals.Mauresmo, playing for the first time Down Under since her Australian Open win last year, fought off three set points in the first before Golovin won in the tiebreaker.Mauresmo, who lost in the first round in Sydney last year, and Golovin each made 43 unforced errors and Golovin had 10 double faults."It wouldn't have been a disaster to lose because obviously that's what I did last year," said Mauresmo, who also won Wimbledon in 2006.Kuznetsova retired from her match against Katarina Srebotnik of Slovenia after Srebotnik won the first set 6-2. Ana Ivanovic of Serbia was ahead 6-2, 4-2 when Petrova decided to retire with stomach muscle problems.Jelena Jankovic, who upset fifth-seeded Martina Hingis in the first round, beat Australian Samantha Stosur 6-2, 7-6 (2). Third-seeded Kim Clijsters beat Nicole Pratt of Australia 6-1, 6-2.