Young Jovan Whitter savoured a major upset victory over top tennis seed James Collieson in the Island Construction Open on Wednesday night.

Taking full advantage of the latter's aggravation of an old wrist injury, Whitter swept to a memorable 2-6, 6-4, 6-2 triumph to advance to the Men's A singles semi-finals.

Collieson was cruising to an easy win, having wrapped up the first set and leading 4-2 in the second.

But suddenly, disaster struck as he re-injured his wrist. Play resumed after an injury time-out and Whitter immediately pounced on his struggling opponent, taking the next four games and the set 6-4. The teenaged fifth seed pressed on in the decisive third set, winning that 6-2.

Number two seed, Jenson Bascome, comfortably took the first set against the sixth seed David Jenkins 6-3, and then withstood a spirited comeback by Jenkins in the second, taking it 7-2 in a tie-breaker to advance to the last four.

Andy Bray, the number three seed and recent winner of the Heineken Open, romped into the semi-finals with a 6-3, 6-1 victory over the eighth seed John Johnston.