BEIJING: The United States regained Olympic track and field superiority with the last two races in the Bird’s Nest yesterday, putting a week of disappointment behind them when they won the 4x400m relays.

In a night of doubles, Ethiopian Kenenisa Bekele completed the elusive 5,000m-10,000m double and Kenya cleaned up the two middle-distance races. Combat sports again provided controversy with a Cuban taekwondo exponent banned after kicking a referee, and a British boxer claiming he was bitten by his Cuban opponent.

On the penultimate day of the Beijing Games China took an unassailable lead on the overall medal table with 49, ahead of the United States on 34, Russia with 21 and Great Britain 19. But victories in the men’s and women’s 4x400m relays lifted the United States to seven athletics titles, one more than Russia and Jamaica with only the men’s marathon today. The US track team, who have suffered a week of upsets including losing their all-around sprint crown to Jamaica, recovered thanks to a remarkable run by women’s anchor Sanya Richards.

The USA self-dubbed ‘Dream Team’ when they came to Beijing have endured a nightmare of disappointing performances including losing their sprint crown when trounced by Jamaica.

But it was the Jamaican-born American Richards who saved face when she took the baton several meters behind Russia’s Anastasia Kapachinskaya and overtook her on the line. Bekele emulated Ethiopian compatriot Tirunesh Dibaba in claiming the long-distance double — the first man to achieve the feat since another Ethiopian Miruts Yifter at the 1980 Moscow Games.

Kenya enjoyed a double gold when Wilfred Bungei won their first men’s 800m title in 16 years and Nancy Langat won the women’s 1500m. Lionel Messi rewarded Argentina in gold for fighting for his right to be at the Olympics when he set up the winning goal in their 1-0 triumph over Nigeria in the men’s football final. In a match played in a sizzling 42 degrees Celsius (107.6 F) inside the Bird’s Nest, the football superstar put Angel Di Maria clear early in the second half and the Benfica player chipped over the goalkeeper.

In the heat of Beijing it was one of the sport’s hottest properties, Messi, who was central to the outcome, and his appearance was only settled a few hours before the first game after his powerful European club Barcelona had blocked their prized striker from taking part.

Violence flared in taekwondo when Cuba’s Angel Valodia Matos kicked a referee in the head after he was disqualfied in his bout.

Matos, a Sydney Olympics winner, was immediately threatened with expulsion from all international competitions.

In boxing, British gold medallist James DeGale claimed he was bitten in his final with Cuba’s Emilio Correa and showed journalists a mark on his chest.

The first-round incident cost Correa two points — the eventual margin of victory.

Boxing’s governing body AIBA also revealed it had been tracking “possible attempts of manipulation” for months before the Games, but insisted no fights had been fixed.

China increased their lead on the medals table with wins in table tennis, and canoeing but missed out on their quest for eight out of eight diving golds when Australian Matthew Mitcham overtook Zhou Luxin with his last dive in the men’s 10m platform final.

The US won their fourth straight women’s basketball crown with a 92-65 triumph over Australia. In a dramatic baseball final, as the sport made its exit from the Olympics schedule, South Korea upset regular gold medalists Cuba 3-2.

Meanwhile, weightlifter Igor Razoronov followed his Ukrainian teammate and heptathlon silver medallist Lyudmila Blonska out of the Games when he became the sixth athlete to fail a drugs test. Raznoronov was unplaced in the -105kg category.