Renowned Asian sprinter Silent Witness stretched his unbeaten record to 15 when he romped to victory in the $576,900 Centenary Sprint Cup (HK-I) at Sha Tin Sunday night. The world's top-ranked turf sprinter was clocked in 56.7 seconds for the 1,000 meters, winning by two lengths in his customary eased down manner over Country Music. Multidandy was third, 4 1/2 lengths farther back. Australia Stakes winner Cape Of Good Hope finished fifth, beaten by 8 1/2 lengths. Silent Witness will make a bid for a 16th consecutive win in the 1,200-meter Chairman's Sprint Prize at Sha Tin on April 3, the final leg of Hong Kong's Champion Sprint Series. Cigar, Citation, and Hallowed Dreams share the record of 16 consecutive wins each.Ridden as usual by Felix Coetzee, the 5-year-old Australian-bred bay gelding raced about a length behind the speed early on, assumed control at the midway point, and drew away inside the final 200 meters to score on a rain-slick course from Country Music.Tony Cruz, Hong Kong's leading trainer, saddled the first three past the post. Silent Witness' latest success took his bankroll beyond HK$40 million for owner Archie da Silva. The owner confirmed that he plans to step Silent Witness up to a mile (1,400 meters) in the Queen's Silver Jubilee Cup (HK-II) on April 24.