Nine-time Wimbledon champion Martina Navratilova believes it would be foolish to write off the Williams sisters as a spent force and backed the American sisters to star at the U.S. Open.

Serena Williams missed 11 months of action after injuring her foot in a freak accident at a German restaurant after winning her fourth Wimbledon title last year and then battled life-threatening blood clots on her lungs.

Rafael Nadal takes an 11-4 winning record into his Wimbledon semi-final against Andy Murray, but insists history will count for nothing in Friday's Center Court blockbuster.

Nadal, the defending champion, is aware that Murray is riding a wave of emotion from a public desperate to see an end to Britain's 75-year wait to crown a new men's singles champion.

Not content with driving a Formula One car, Australian star Mark Webber now wants to fly planes and Qantas plans to help him.

The 34-year-old Red Bull driver used a B737 flight simulator ahead of the Australian Grand Prix in Melbourne this year and spent time at Heathrow airport in London on Wednesday in the cockpit of a A380 with a training captain.

Chelsea manager Andre Villas-Boas was quick to dismiss comparisons with Jose Mourinho as he used his official introduction at Stamford Bridge to insist he is not the new 'Special One'.

Villas-Boas worked for Mourinho as an opposition scout during his fellow Portuguese's time in charge at Porto, Chelsea and Inter Milan and has spent much of his brief managerial career following in the footsteps of the controversial coach.

When Maria Sharapova says her game is getting better and better at Wimbledon, it's hard to argue.

The fifth-seeded Russian, the only quarter finalist at the All England Club with a Grand Slam title to her name, dominated her match on Center Court on Tuesday, moving back into the semifinals for the first time since 2006.

Andy Murray's campaign to end Britain's 75-year wait for a Wimbledon men's singles champion could be boosted on Tuesday by Rafael Nadal's knife-edge survival battle to overcome a crippling left foot injury.

Murray, the fourth seed, sailed into the last eight with a straight sets win over Richard Gasquet and was safely back in his London home when scheduled semi-final opponent Nadal suffered a potentially tournament-ending blow.

Defending champion Serena Williams was dumped out of Wimbledon here Monday, losing to French ninth seed Marion Bartoli in straight sets 6-3, 7-6 (8/6).

Four-time winner Williams, who has only recently returned to tennis after a year-long lay-off because of health and injury problems, was always struggling to impose herself against her determined French opponent on Court One.

Red Bull driver Sebastian Vettel won his sixth race of the season at the European Grand Prix on Sunday to further strengthen his already commanding Formula One championship lead.

Vettel beat Fernando Alonso of Ferrari by 10.891 seconds for his second straight victory along Valencia's street circuit. It was the German's fifth win this season starting in pole and came in stifling 46 degrees Celsius (115 degrees Fahrenheit) heat.

Defending champion Rafael Nadal's Wimbledon campaign runs into the imposing 1.98m (6ft 6ins) figure of danger man Juan Martin del Potro Monday while the rejuvenated Williams sisters eye another final date.

World number one Nadal, the 2008 and 2010 winner, has the toughest-looking clash of the fourth round when he tackles Argentine del Potro, the man who blew him off court in the US Open semi-finals in 2009 for the loss of just six games.

Seventeen of Libya's top football figures, including national team goalkeeper Juma Gtat, have defected to rebels battling to oust the country's leader Moammar Gadhafi, the BBC reported on Saturday.

Three other national team players and the coach of Tripoli's top club al-Ahly, Adel bin Issa, have also defected, in what the BBC described as "clearly a propaganda blow" for Gadhafi in "football-mad North Africa."