Jamaican Asafa Powell clocked 9.96 seconds in a guest appearance at the SAGICOR Trinidad and Tobago National Championship as he won his 100-metre semi-final on Saturday evening.

Powell's time makes him the fourth fastest in the world this year behind Jamaican world record holder Usain Bolt (9.72), American Tyson Gay (9.85), and Trinidad and Tobago's Richard Thompson (9.93).

Thompson was second to Powell in 10.11 seconds in wet conditions.

Competing for the first time since a pectoral muscle injury - from weight training - in April, Powell did not contest the final, which Marc Burns won in 10.01 seconds.

Hundreds of fans at the Hasely Crawford Stadium watched Powell rally from a moderate start to surge past Thompson for the victory as he tunes up for a showdown with Bolt at the June 27-29 Jamaica National Championship in Kingston.

The eventual final had a dramatic finish with race favourite Darrel Brown, falling near the finish.

Brown, a training partner of Powell, was perfectly positioned for a victory when he and Thompson bumped into each other shortly after the midway point in the sprint.

Brown, a World Championship silver medallist in 2003, tumbled over on the track and Burns completed a victory.

Thompson struggled to keep his balance and held on for second in 10.10 seconds, the same time given to third-placed Aaron Armstrong.

Keston Bledman was fourth in 10.18 seconds.

In the women's 100-metre final, the new US Collegiate champion Kelly-Ann Baptiste was unchallenged in victory.

The Louisiana State University (LSU) star took control early, stopped the clock in a brisk, wind-assisted time of 11.01 seconds.

Her own national record of 11.06 stands because of a following wind of 2.7 metres per second.