Dudi Sela reached his first ATP Tour quarterfinal in more than a year-and-ahalf on Wednesday, advancing to the last eight in the Chennai Open with a 4- 6, 6-2, 6-4 victory over Benoit Paire.The 26-year-old Israeli failed to make a single quarterfinal in 2011, but he has got the new year off to a very encouraging start, already guaranteeing himself a jump of around 10 places from his current position at No. 83 in the world rankings.Reuters contributed to this report.After losing the opener to the Frenchman by dropping his serve in the 10th game, Sela bounced back immediately with a break in the first game of the second set and soon tied up the match.The first six games of the decisive set went according to serve, but Sela recorded the crucial break in the seventh game and held his serve to finally reach the last eight of a tournament for the first time since Queens in June 2010.Sela, who hasn’t played in a semifinal in exactly two years since losing to Stanislas Wawrinka in the last four in Chennai in 2010, next plays fourth seed Milos Raonic (31), the 2011 ATP Newcomer of the Year, who beat Victor Hanescu 6-1, 6-4.Meanwhile, it took Andy Ram and Yoni Erlich almost five months to reach their first semifinal last year, but like Sela, they have also got 2012 off to a promising start, advancing to the last four in Chennai on Wednesday with a 6-3, 6-3 victory over Nicolas Almagro and Pere Riba.In other action, top seed Rafael Nadal cruised into the quarterfinals of the Qatar Open with a routine 6-2, 6-2 victory over qualifier Denis Gremelmayr on Wednesday.The unfancied German had won a solitary game in their only previous meeting and fared little better in windy Doha, Nadal pounding his fellow lefthander from the outset.“The conditions weren’t easy, you try to move your legs at the last moment,” the Spaniard said in a courtside interview.“I didn’t have a chance to practice a lot in the off-season, not as much as I would have liked. These matches are really important and the best practice I can have.”Roger Federer also encountered little trouble on his way to the last eight, defeating Grega Zemlja 6-2, 6-3.Also, former world No. 1 Serena Williams suffered an injury less than two weeks ahead of the Australian Open on Wednesday when the American was forced out of the Brisbane International with a badly twisted ankle.There was also bad news for home favorite and top seed Samantha Stosur, who was bundled out early for the second successive year.Men’s top seed Andy Murray was in danger of joining Stosur in an early exit when he dropped the first set against Luxembourg’s Gilles Muller before he fought back through a second set tiebreak then blitzed the decider to run out a 4-6, 7-6, 6-0 winner in just over two hours.The 24-year-old world No. 4, who also struggled in the first round on Tuesday before he beat the unheralded Mikhail Kukushkin in three sets, now meets Marcos Baghdatis in the quarterfinals.Williams twisted her left ankle late in her second round match against Serbia’s Bojana Jovanovski and needed about 10 minutes of treatment, including restrapping her ankle, before she went on to secure a 6-2 6-4 victory.The American had scans later which confirmed she would need to withdraw from the tournament.She had been due to meet Slovakia’s Daniela Hantuchova in the quarterfinals and the injury will now create some doubt as to whether the 30-yearold will be in top form as she attempts to win her sixth Australian Open title at Melbourne Park.“I’m disappointed to have to pull out of the Brisbane International,” Williams said in a statement. “I have been to hospital and it has been confirmed that I have a left ankle sprain that I probably shouldn’t play on. “I’m going to take a couple of days off, not too many, and see how I feel.“I’m still hopeful of playing the Australian Open.”The first grand slam of the season starts on January 16.Stosur, who beat Williams in the US Open final last year to claim her maiden major title, continued her poor run of form in her home town losing 6-4, 6- 2 to Czech Iveta Benesova.