Halfbridled first hinted at brilliance when she sailed to victory in her career debut on July 27, 2003 at Del Mar. In her next two starts, she captured the Grade 1 Del Mar Debutante and Grade 2 Oak Leaf Stakes at Santa Anita Park. She capped her undefeated season with a clear triumph in the Breeders’ Cup Juvenile Fillies at Santa Anita Park and was named Eclipse Award champion two-year-old filly.
Halfbridled returned to action the next year with a runner-up effort in the Grade 1 Santa Anita Oaks before closing her career with a second-place effort in the Grade 2 Beaumont Stakes at Keeneland Race Course. The daughter of 1990 Breeders’ Cup Classic winner Unbridled never finished worse than second and earned just shy of $1-million. Richard Mandella trained her for Wertheimer Farm and she holds a special footnote as the first Breeders’ Cup winner in a non-steeplechase race to be ridden by a female jockey, Julie Krone.