You could call it the showdown and the sideshow as the world’s fastest sprinters and Dwain Chambers set their sights on the same goal this weekend. Usain Bolt, the 100 metres world record-holder, goes head to head with Asafa Powell, the previous incumbent, at the Jamaica Olympic trials, while Tyson Gay, the doughnut-munching great American hope, is aiming to emerge from the sudden-death drama of the United States version.

Then there is Chambers, who is still chasing the Olympic qualifying time that will spark a High Court dash for a place at the Games in Beijing in August. He is scheduled to run in Biberach, Germany, tomorrow afternoon, several hours before the all-Jamaican duel in Kingston.

Powell started the season as the world record-holder at 100 metres, but Bolt, a 6ft 5in 200 metres specialist, shook up the status quo when he ran 9.72sec in New York last month. “Bolt is my main threat,” Powell said. “Tyson Gay is the only man outside of the Caribbean who can deny us.”

Powell has previously been capable of beating himself, too. He admitted that he “panicked” during the World Championship final in Japan last year, enabling Gay to help himself to the gold medal. As for Bolt, he would have to possess superhuman ambivalence to carry out a veiled threat to ignore the 100 metres in Beijing.

Powell, who ran 9.96 on his return from a chest injury last week, emphasised that the trials are about qualifying for the Olympics rather than securing bragging rights.

A bad start late on Sunday night and Gay may not make it to China because only the first three in each event will qualify for the US team. It is a brutal system that has claimed notable scalps since its introduction in 1972. Last year, Sanya Richards, the world’s best 400 metres runner, failed to qualify for the World Championships because she was ill with Behçet syndrome, a condition that affects the immune system, and finished fourth.

Justin Gatlin’s dream of defending his 100 metres title in Beijing is over after his court appeal to run in the US trials was rejected last night. Gatlin is suspended for four years for doping violations.

Chambers is seeking a mark of 10.21 in Biberach, while believing that he is in 10.1 shape or better. If he gets the qualifying time, a legal challenge to the British Olympic Association bylaw banning all doping offenders from competing at the Olympics will be lodged next week.

He will have his work cut out to finish in the top two at the trials in Birmingham on July 11 to 13 regardless of his legal action. Tyrone Edgar has run 10.06 this season, Marlon Devonish believes that he can double up at the 100 metres and 200 metres, and other athletes, such as Harry Aikines-Aryeetey and Craig Pickering are confident that they can beat Chambers.