LONDON: China's Liu Xiang left the Olympic stadium in a wheelchair yesterday after hitting the first barrier in a 110 metre hurdles heat while Jamaican Usain Bolt breezed through an "easy" 200 qualifier in his favourite event.

The contrasting fate of two of the world's most famous athletes made for a striking opening to the 11th full day of competition in London, where Britain celebrated a 22nd gold to make it the hosts' most successful Olympics in 104 years.

Liu's dreams of glory, however, were shattered in a cruel echo of his early exit from Beijing four years ago and indications were that it was the same Achilles injury that led to his fall on a cool, cloudy morning in London.

China's first male gold medallist on the Olympic track after triumphing in 2004, Liu remains his country's most popular sportsman alongside former basketball player Yao Ming.

Fans at home quickly took to social networking websites to voice their dismay.

Bolt, who set the second fastest time ever in his weekend 100 triumph, brimmed with confidence after comfortable qualification for the 200 semis before another capacity 80,000 crowd at the main stadium.

He remains on course for an unprecedented Olympic sprint "double-double" at tomorrow's final.

Home nation Britain surpassed the heroics of four years ago, when they picked up 19 gold, by amassing 22 and counting.

Triathlete Alistair Brownlee crossed the line in central London's Hyde Park draped in the Union flag to make it 19 before Britain's riders triumphed in the dressage arena at Greenwich Park.

Laura Trott then took another gold in the cycling track omnium. Chris Hoy triumphed in the keirin event, clinching his sixth Olympic gold medal to ensure Britain matched their Beijing record of seven track titles in cycling.

Brownlee's younger brother Jonathan was third in the gruelling triathlon, making them the first siblings to feature on the Olympic medal podium together in an individual event for more than 50 years.

British medal haul yesterday strengthened their third place in the overall medals table, success which has helped fuel huge Games excitement across the country.