Roger Federer through to semi-finals at Tour finale

LONDON (Reuters) - Roger Federer produced some exhibition tennis to beat Robin Soderling 7-6 6-3 on Thursday and become the first player through to the semi-finals of the ATP World Tour Finals.

Roger Federer

The Swiss world number two, bidding for a record-equaling fifth title at the lucrative season-ending tournament, squandered a break of serve in the first set as Soderling forced a tiebreak but was always in control of the Group B clash.

Federer got lucky on set point when Soderling elected to leave a backhand that floated on to the line but he required no help from the Swede to close out the match.

He broke in the eighth game of the second set with a couple of classy points and completed his 15th victory in 16 encounters with Soderling in 88 minutes.

“It’s the worst feeling in the world when you leave a shot like that, you have a split second to decide, and then see it go in,” Federer said of his lob winner at 6-5 in the tiebreak. “I got lucky on that shot and overall played a good match.” Federer’s third consecutive round robin victory was also good news for Britain’s Andy Murray, who should also qualify for the semi-finals unless he loses heavily to Spain’s David Ferrer later on Thursday.

Soderling, who finished his group matches with one victory against Ferrer, could still hypothetically qualify for the semis although he looked resigned to an early flight home as Federer turned on the style in the O2 Arena.

Serena Williams out of Aust Open

Serena Williams

Two-time defending champion Serena Williams has withdrawn from January’s Australian Open after undergoing a second bout of foot surgery.

Williams, the winner of 13 grand slam titles including five at Melbourne Park, informed tournament officials of her decision to pull out on Thursday. “As I continue to rehabilitate my foot after the second surgery last month, it is with the utmost regret that I am withdrawing from the Hopman Cup and the 2011 Australian Open Championships,” she said in a statement.

“As I recently learned, pushing myself back into my intense training too early only caused me further injury and damage. “While I desperately want to be back on the court and competing in the first grand slam tournament of the year, it is imperative for my health that I continue to work with my doctors to ensure my foot heals properly.

“This decision, though heavy on my heart, is the right one.

“I am praying for a healthy recovery and I promise my Aussie fans and my fans around the world that I will be back better than ever as soon as I can be.”

Williams, 29, has not played competitively since beating Russian Vera Zvonareva in the Wimbledon final in early July.

The American is currently ranked fourth in the world.