Mainstay made her debut at Monmouth Park on Jun. 4, 2021. She splashed her way to a 7 3/4-length win over a sloppy track, cruising in gate-to-wire style under jockey Frankie Pennington.
Mainstay is sired by Australian-bred stallion Astern. She's a half-sister to 2020 Breeders' Cup Juvenile Fillies winner Vequist.
Stay up-to-date with the best from America's Best Racing!