The London 2012 Olympics could give a £13 billion stimulus to the British economy over the next four years, Prime Minister David Cameron said Thursday.

Outlining his vision for turning the event "into gold for Britain," the premier said the country was set to host an "outstanding Games" and that he expected their full cost to be recouped over time.

Lewis Hamilton is hoping that the latest upgrades to his McLaren car and significantly cooler conditions will boost his chances of delivering a home win to enhance his title challenge in Sunday's British Grand Prix.

The 27-year-old Englishman, who crashed out of third place at last month's sizzling European Grand Prix in Valencia, slipped from leading the drivers' title race to third and is now 23 points adrift of Fernando Alonso of Ferrari.

Serena Williams and Agnieszka Radwanksa will meet in Saturday's Wimbledon final in a battle of raw power against slender poise and expectation over hope.

Four-time champion Williams, the 30-year-old sixth seed, buried Victoria Azarenka under a record firestorm of 24 aces to reach her seventh Wimbledon final on Thursday, winning 6-3, 7-6 (8/6).

Spanish Formula One driver Maria De Villota has lost her right eye as a result of an accident she suffered during testing in England on Tuesday, her Marussia team said Wednesday.

De Villota was rushed to Addenbrooke's Hospital in Cambridge on Tuesday after a crash at Duxford Airfield circuit in Cambridgeshire, eastern England.

Kenya and Ethiopia are set to continue their traditional role as the strongest African medal contenders at the Olympics.

While South Africa may be unable to match the men and women from East Africa in podium appearances, they are desperate to better a dismal showing in Beijing four years ago when 253 athletes delivered just one medal between them.

Robin van Persie has rejected the offer of a new Arsenal contract, the striker announced via his official website on Wednesday.

The Dutch international has a year left on his current deal with the English Premier League club, who could now be tempted to cash in on their prize asset, rather than see him leave for nothing on a Bosman free transfer at the end of next season.

Brazil's Corinthians won the Copa Libertadores for the first time, defeating Argentina's Boca Juniors 2-0 in the second leg of the final before an ecstatic home crowd of 40,000.

The Corinthians late Wednesday prevailed 3-1 on aggregate as the two teams drew the first leg 1-1 in Buenos Aires last month.

Roger Federer earned a record 32nd Grand Slam semifinal berth and moved closer to a record-tying seventh Wimbledon title when he beat Mikhail Youzhny 6-1, 6-2, 6-2 Wednesday.

Federer's opponent Friday will be defending champion Novak Djokovic, who beat Florian Mayer 6-4, 6-1, 6-4.

Rafael Nadal, knocked out of Wimbledon in the second round last week, is to take two weeks off because of tendonitis in his knee.

The Spaniard will miss a charity match against world number one Novak Djokovic in Madrid's Bernabeu stadium on July 14 but hopes, however, to have fully recovered in time for the July 27-August 12 Olympics in London.

Oscar Pistorius will become the first double amputee to compete at the Olympics after being included Wednesday in the South African 4x400-meter relay team for 2012 London Games, an official said.

The 25-year-old's selection comes five days after conceding defeat in a battle to run in the 400m at the Games as he finished 0.22 of a second outside the qualifying mark of 45.30 seconds when coming second at the African championships in Benin.