Ocean Silk, the 7-10 favorite who arrived only recently from Europe, rallied from far back to finish second, three-quarters of a length in front of Peacefally (IRE).
It was the sixth win in 19 starts for Spice Island, who is owned by Denlea Park Ltd. and trained by John S. Pregman, Jr. She increased her career earnings to $302,656.
Spice Island paid $25.60, $7.60 and $5.
Velasquez, who was riding his third winner of the day, said, "We had a great trip all the way and when we turned into the stretch I had a lot of horse left."
Ocean Silk brought two wins into the race along with a runner-up finish in the Yorkshire Oaks (Eng-I). She paid $3 and $2.40.
"She had absolutely no run on her mind at all," said jockey Pat Day. "Everything she did, I had to make her do. Even though she put in a good finish at the end, she was under duress."
Peacefally paid $7 to show. Alternate finished fourth, followed, in order by Beyond the Waves, Golden Rhythm, Kabylia (IRE), Snow Dance, Miss Goosebumps and Still As Sweet (IRE).
Keeneland's attendance Sunday was 13,824.