ATP

• Federer, Murray win; Roddick pulls out in Shanghai

  
  

  Shanghai, China (Sports Network) - U.S. Open champion Roger Federer and U.S. Open runner-up Andy Murray posted round-robin wins, while former world No. 1 Andy Roddick pulled out of his scheduled match against Federer at the $4.45 million Tennis Masters Cup. Murray qualified for the semifinals with his victory on Wednesday.

  The top-seeded and two-time defending Masters Cup champion Federer was scheduled to battle the fifth-seeded Roddick on Day 4 here, but Roddick (0-1) pulled out of this week's four-player Red Group due to an ankle injury. The big-serving American was replaced in the field by 27th-ranked alternate Radek Stepanek of the Czech Republic.

  Roddick sustained the injury while practicing here on Tuesday.

  "When I was doing a warm-up drill in practice I just went over on it," Roddick said. "We tried as much as we could to get it better." The former U.S. Open champion Roddick, who lost to Murray here on Monday, is now done for 2008 and will return to ATP action in January. The American star went 49-18 this season, including three titles.

  The 13-time major titlist Federer snuck past the veteran Stepanek 7-6 (7-4), 6-4 on the indoor hardcourt at Qi Zhong Stadium. The Swiss needed 1 hour, 41 minutes to prevail, which he did with the help of three service breaks, compared to two for the Czech loser (0-1).

  Federer is now 7-2 lifetime against Stepanek, including 3-1 this year. The Czech stunned the Swiss in Rome back in May.

  The four-time overall Masters Cup titlist Federer is now 1-1 this week and will meet the third-seeded Murray here on Friday with a possible trip to the semifinals at stake for the former top-ranked superstar. It will mark a rematch of September's U.S. Open finale, which was won by Federer.

  Murray is 3-2 lifetime against Federer, including a 2-1 record this season.

  The reigning five-time U.S. Open champion Federer beat Spain's David Ferrer in last year's Masters Cup final. The Swiss great is the only former Masters Cup champ in this year's field.

  Also on Wednesday, the high-flying Murray mauled eighth-seeded Frenchman Gilles Simon 6-4, 6-2 in 1 hour, 33 minutes to move to a perfect 2-0 in the Red Group. Simon (1-1) shocked Federer here on Monday.

  Murray broke Simon's serve on four occasions on Wednesday, while the overmatched Frenchman settled for only one break in defeat. The Brit is now 3-0 against Simon this year.

  The red-hot 21-year-old Murray has won 16 of his last 17 matches overall, including some titles in St. Petersburg and Madrid.

  On Thursday, second-seeded Serbian Novak Djokovic (2-0) will face sixth-seeded Frenchman Jo-Wilfried Tsonga (0-2) and fourth-seeded Russian Nikolay Davydenko (1-1) will tangle with seventh-seeded Argentine Juan Martin del Potro (1-1) in some Gold Group action. Djokovic beat Tsonga in the Australian Open final way back in January.

  Djokovic has already qualified for Saturday's semifinals, while Davydenko-del Potro will decide the other final-four combatant from the Gold Group. Tsonga has already been eliminated from semifinal contention.

  Davydenko and del Potro have split two career matchups, with the Argentine winning their lone meeting this year, in the Davis Cup semifinals.

  Murray, Tsonga, del Potro and Simon are all making their Masters Cup debuts this week.

  11/12 09:50:18 ET