It's a motor rally with a difference: souped-up "green" vehicles going head to head in an international eco-marathon to see who runs the longest on as little energy as possible.

Germany's Eurospeedway Lausitz, around 130 kilometers (80 miles) south of Berlin, is hosting the Shell Eco-marathon this week where nearly 3,000 participants are putting the world's most fuel-efficient vehicles to the test.

Kim Clijsters crashed out of Roland Garros on Thursday, her worst Grand Slam result in nine years, while Maria Sharapova escaped humiliation at the hands of a fearless 17-year-old French girl.

Second seed Clijsters let slip a set and a 5-2 lead, and squandered two match points, to slump to a stunning 3-6, 7-5, 6-1 second round defeat to Dutchwoman Arantxa Rus, the world number 114.

Novak Djokovic and Juan Martin del Potro will put their close friendship aside on Friday when they clash for a place in the French Open last 16, the tournament's biggest match-up so far.

Djokovic is the overwhelming favorite not just to see off the giant 1.98m Argentine, but also go on to take the title off Rafael Nadal and assume the world number one spot.

Manchester United are seeking to banish the memory of their 2009 humbling by Barcelona as they prepare for Saturday's Champions League final at Wembley.

Two years ago, Sir Alex Ferguson's side arrived in Rome brimming with confidence, ready to justify their status as the bookies' favorites by becoming the first side to clinch back-to-back titles.

Rafael Nadal admitted he feared he might never break John Isner's huge serve, after coming through a thrilling five-set match against the American to reach the French Open second round.

The defending champion and top seed, bidding for a record-equalling sixth Roland Garros crown, was staring down the barrel of a shock elimination after allowing Isner to establish a 2-1 sets lead.

Novak Djokovic took his unbeaten record in 2011 to 38 wins on Monday before Grand Slam king Roger Federer demonstrated to the unstoppable Serb that he is still a French Open force.

Second seed Djokovic enjoyed a 6-2, 6-1, 6-3 dismissal of hapless Dutchman Thiemo De Bakker in the first round before 16-time Grand Slam title-winner Federer romped to a 6-3, 6-4, 7-6 (7/3) win over Spain's Feliciano Lopez.

Barcelona's two-time world player of the year Lionel Messi has dismissed suggestions that Manchester United lack the quality of previous squads ahead of the two sides' Champions League final on Saturday in London.

The match will be a repeat of the 2009 final in Rome when Barcelona beat Manchester United 2-0, with Messi scoring the second goal.

A day after the tournament began, the French Open is really about to get started.

The opening day at Roland Garros featured 32 matches on eight courts, with three seeded players already falling by the wayside.

From the moment Carlo Ancelotti discovered that his trusted assistant Ray Wilkins had been sacked without his knowledge, the Chelsea manager knew he was on borrowed time at Stamford Bridge.

Ancelotti was sacked by Chelsea on Sunday less than two hours after his side concluded a disappointing season with a 1-0 defeat at Everton.

World number one Rafael Nadal has a record-equalling sixth French Open in his sights, but the Spaniard believes undefeated Novak Djokovic will start Roland Garros as title favorite.

Something has got to give over the next two weeks.