AMERICAN dominance of the Olympic athletics track is over. Nowhere has this been more evident than in the sprints.

The superpower of sprinting is no more. Jamaica's Usain Bolt won the 100m and 200m sprints, once almost the sole preserve of Americans, and Bolt's female compatriots dominated the women's events at Beijing.

Jamaican Shelly-Ann Fraser won the women's 100m and yesterday Veronica Campbell-Brown made it a double for the Caribbean nation in the 200m. No wonder some wags are calling these games the "Jamaican Olympics".

Even the overall supremacy of the US is no longer. The US has won the gold medal count at nine of the 15 Olympic games since World War 2 (they boycotted the 1980 games in Moscow).

The rising power in the games is China. From virtually nowhere on the medals table, China was third in 2000 in Sydney and second, ahead of Russia, in Athens four years ago. Today, they lead the medals table and are expected to finish top in their home town Olympics.

The US was once almost unchallenged in the sprints. Of the 15 post-war games, the Americans won seven 100m-200m sprint doubles. Twice the same man did it: Bobby Joe Marr in 1956 and Carl Lewis in 1984. And when they did not manage the 100m-200m, they often did the 200m-400m - in the unique case in 1996, by a single person: Michael Johnson.

In 1956, at Melbourne, the Americans won the 100m, 200m, 400m and 800m.

This year, they picked up the scraps. Yesterday, LaShawn Merritt won the 400m for a rare US triumph. He overpowered a team-mate, reigning Olympic and world champion Jeremy Wariner, to win in a lifetime best 43.75sec, a time only four runners in history have bettered. Wariner was a stunned second in 44.74 with David Neville completing a US sweep in 44.80.

But disaster awaited them in the 4x100m relay, in which the men's and women's teams were eliminated because of botched switch-overs. It was symbolic of the shambles that has been the US challenge in Beijing. In the past, the US men won 15 4x100m relay gold medals.

Yesterday's disasters continued a nightmare week for a squad dubbed a "Dream Team" by US men's coach Bubba Thornton.

For the first time since 1980, the US failed to win at least one 100m or 200m crown.

Cuba's Dayron Robles won the 110m hurdles in 12.93sec, another event in which the US has been strong. At least Americans David Payne and David Oliver were second and third.

Jamaica's star-studded squad continued to shine. Olympic women's 100m champion Fraser, Sheri-Ann Brooks, Aleen Bailey and Campbell-Brown - Campbell-Brown running less than an hour after defending her 200m crown - won their 4x100m relay heat in 32.24, the year's best time. Campbell-Brown won the 200m earlier in a personal-best time of 21.74sec.

"It's great to come out and defend my gold medal," Campbell-Brown said. "It has been great to see Jamaica get a clean sweep of the sprints."

Her victory followed a Jamaican women's 100m medal sweep and the domination of Bolt, who did not run on the Jamaican relay in qualifying. But he plans to run in today's final.

Dwight Thomas, Michael Frater, Nesta Carter and former 100m world record-holder Asafa Powell assured Bolt's chance for a third medal by winning their heat in 38.31 seconds. - Reuters and Sapa-AFP