Donetsk (Ukraine), Jul 14 (IANS/CMC): Jamaica continued its domination of the sprint hurdles as Marvin Williams clocked a new World Youth leading time of 50.39 seconds to win the Boys' 400 metres Hurdles at the 8th IAAF World Youth Championship.

Williams surprised his rivals including teammate, classmate and training partner Okeen Willliams to take the gold medal Saturday, the fourth for Jamaica in the tally, reports CMC.

Okeen, the pre-race favourite and with 50.53, the fastest time in the world to win his semi-final, fell on the penultimate hurdle.

Marvin finished ahead of Yang Wang of China in 50.78 and American Kenneth Selmon in 51.30.

In the girls' equivalent, Tia-Adana Belle of Barbados clocked a personal best of 58.42 to secure silver behind South African Helene Swanepoel with a World Youth leading time of 58.08.

Jamaica leads the medal tally with six including four gold medals, followed by Australia with three and China with two gold medals. Cuba and Barbados are the only other Caribbean countries with medals - Cuba (one gold, one silver and one bronze) and Barbados with one silver medal.