Uni repaid connections' faith in supplementing her for $100,000 when romping home in the Breeders' Cup Mile at Santa Anita.
The Chad Brown-trained five-year-old took the valuable first prize thanks to a telling burst of speed, to score from Got Stormy, the only other female runner in the field.
True Valour was quickly away, but James Tate's Hey Gaman - the mount of Frankie Dettori - and El Tormenta shared the lion's share of pace-making duties until the business end.
Uni (7-2) and Got Stormy were both delivered wide and it was Joel Rosario and the mare that won the day, by a length and a half. Brown saddled the third home, Without Parole, who was formerly with John Gosden, edging Aidan O'Brien's Circus Maximus.
O'Brien said: "He was a little bit slow into his stride, and then was beaten on the bob for third, but I was pleased with his run. He's run a solid race."
It was a double on the card for Rosario after his victory on Covfefe in the Filly & Mare Sprint.
"She's a remarkable little horse," said Brown.
"She's got the best turn of foot I've ever trained. The last quarter, I don't think I've had a horse like her."