Two-time world MotoGP champion Casey Stoner has announced he will quit motorcycle racing at the end of the season for "family reasons."

Stoner, who has won 35 MotoGPs in his career and leads the current standings after winning two of the season's three events, made the announcement at a news conference ahead of Sunday's French Grand Prix.

Novak Djokovic, Rafael Nadal, and Roger Federer reached the Rome Masters quarterfinals on Thursday, but fourth seed Andy Murray suffered another setback in his French Open plans when he crashed out to Richard Gasquet.

Murray, who lost 6-7 (1/7), 6-3, 6-2 to the Frenchman, revealed that he has been carrying a back problem since December, but declined to go into details on the symptoms or its treatment.

The American University of Beirut held a send-off ceremony on May 16 for two of its students who will be representing Lebanon in tae kwon do and table tennis at the 2012 Olympics in London, a press release said Thursday.

Andrea Paoli, a business junior, and Tvine Moumjoghlian (BA in economics, 2010), will be heading to London in July to represent Lebanon in tae kwon do and table tennis respectively.

A Frenchman who lost his limbs in an electrical accident swam from Papua New Guinea to Indonesia in strong winds and currents Thursday, finishing the first stretch in a mission to swim between five continents.

Philippe Croizon, 43, who swam the English Channel in 2010, left Papua New Guinea's fishing village of Wutung in the early morning to begin what he has billed as the Oceania-Asia stretch of his challenge.

NBA scoring champion Kevin Durant struck for 22 points, five coming in a game-ending 9-0 run, as Oklahoma City stunned the Los Angeles Lakers 77-75 in the NBA playoffs on Wednesday.

The Thunder, unbeaten in six playoff games, seized a 2-0 lead in the best-of-seven Western Conference second-round series, which shifts to Los Angeles for games three and four on Friday and Saturday.

Kevin Garnett scored 27 points while Paul Pierce added 24 and Rajon Rondo had 23 as Boston cruised past Philadelphia 107-91 on Wednesday to grab the lead in their NBA playoff series.

The Celtics traded one-point victories with Philadelphia in the first two games in Boston, but their stars dominated early on the way to the team taking a 2-1 edge in the second-round Eastern Conference best-of-seven series.

Roger Federer and Rafael Nadal stepped up their preparations for the French Open a gear as both advanced without any problems in their opening matches at the Rome Masters here on Wednesday.

Federer's last minute decision to compete was rewarded immediately as he coasted to a 6-3, 6-4 second-round win over Argentinian journeyman Carlos Berlocq.

FC Barcelona's Brazilian star Dani Alves is expected to be out of action for up to two months after undergoing surgery on Wednesday on a broken collarbone, the Spanish club announced.

"The expected recuperation period is to be between six and eight weeks," the Primera Liga side said, adding that the player would leave hospital on Thursday.

Striker Carlos Tevez insisted Wednesday he would not apologize to Sir Alex Ferguson after waving a mocked-up tombstone of the Manchester United boss during Manchester City's Premier League title celebrations.

"It seems that Ferguson is the president of England. Because each time that he speaks badly of a player or talks nonsense about me no-one comes out to say that he has to apologize.

Liverpool legend Kenny Dalglish was sacked as manager of the club on Wednesday in a dramatic move by the club's owners following a disappointing Premier League campaign.

The 61-year-old Scot, who had returned for a second stint as manager at Anfield in January last year, paid the price for a dismal season which saw Liverpool finish 37 points behind champions Manchester City.