Chambers sixth in Puerto Rico

Dwain Chambers finished a disappointing sixth at the Ponce Grand Prix in Puerto Rico on Saturday.

It was Chambers' first 100 metres race since being cleared to compete at this summer's London Olympics.

Trinidad & Tobago's Keston Bledman claimed victory in 10.12 seconds, with Jamaica's Nickel Ashmeade second in 10.15secs and American Trell Kimmons third (10.18). Chambers, 34, was well back in 10.52 - also beaten by fellow Briton Tyrone Edgar, who was fourth in 10.42.

Chambers, who was banned for two years in 2004 after testing positive for a banned steroid, was prevented from participating at the Beijing Games but is eligible for selection for London after the British Olympic Association's lifetime ban for drugs cheats was last month ruled non-compliant by the Court of Arbitration for Sport.