Oleksandra, winless in three starts in Australia in 2017, overcame a slow start to win her American debut in a maiden race on the hillside turf course in Friday's second race.
Ridden by Mike Smith for trainer Neil Drysdale, Oleksandra needed every bit of the about 6 1-2 furlongs to reach the front, edging pacesetter Magical Gray, a 21-1 chance, by a neck.
Oleksandra races for the Team Valor International partnership, which bred the filly in Australia. Oleksandra is owned by Animal Kingdom, the 2011 Kentucky Derby winner who raced for Team Valor.