A furlong from the finish, Hawaiian Sound looked the likely winner but Shirley Heights was making rapid progress in fourth.
Shirley Heights was given a rating of 130 by the independent Timeform organisation, placing him eight pounds behind the top-rated horse Alleged.
The Sunday afternoon food and music sessions at Antigua's Shirley Heights are aimed mainly at tourists, including cruise ship passengers.
Prominent on the list of historic sites to be restored are the fortifications of Shirley Heights, overlooking the dockyard.
On Shirley Heights itself, the visitor passes one crumbling building after another, the remains of a mighty complex.
Above the harbour at Shirley Heights there's a "jump up" on Sunday evenings, with rum punches, a barbecue and steel band.
Slip Anchor, was sired by the 1978 Derby winner Shirley Heights.
She is the granddaughter of Northern Dancer, her damsire is Shirley Heights.
The best place for fans to watch the races start on the first day is at Shirley Heights, where breakfast and the music of a steel band accompany the view.
The inaugural running was won by the subsequent Derby winner Shirley Heights.