LEXINGTON, Ky. - It was all going to be so fitting. Juddmonte Farms sponsored the Spinster Stakes at Keeneland, and there came the Juddmonte homebred Proviso, making her North American debut Sunday, racing to the eighth pole with a clear lead in the .\nAnd then Proviso turned right.\nIn so doing, she cut off the surging run of Mushka, and after a relatively short review of the stretch action, Keeneland stewards disqualified Proviso to second, placing Mushka first.\n"When she made the lead, her head came straight up, and I thought she might do something," said Proviso's disappointed jockey, Rajiv Maragh. "I had my stick in my left hand, but I never even hit her with it."\nOn the phone with the stewards, Desormeaux said he would have won had not Proviso come out. "She stopped all my momentum," Desormeaux said.\nA few minutes later, Desormeaux said he felt Mushka had Proviso measured at the sixteenth pole, just when Proviso came out.\n"The leader just stopped, and she stopped right in my path," Desormeaux said.\nMushka indeed lost her action, as Proviso went on to a 1 1/4-length victory, but the outcome quickly was reversed. Mushka ($12.40), whose best previous win had come in the 2007 Demoiselle Stakes on dirt, paid $12.40 to win, and was timed in 1:49.01 for the 1 1/8 miles on Polytrack. Teamgeist finished third, while 3-1 favorite Swift Temper was 10th of 11.\n"In the middle of the backstretch I had to encourage her," said Swift Temper's rider, Robby Albarado. "That's not her."\nProviso had made her first 15 starts in Europe, and Sunday's race - where she ran under trainer Bobby Frankel's name - was her first in the U.S. Both she and Mushka benefited from racing well behind a hot pace Sunday, with Be Fair leading Champagne Eyes and Ginger Brew through splits of 23.85 seconds for the first quarter-mile, 46.96 for the half, and 1:11.12 for six furlongs. Proviso, eighth after three-quarters of a mile, made a decisive upper-stretch move between horses to take the lead, while Mushka, who rallied from 10th, came six wide into the stretch - their paths finally crossing in an unfortunate fashion.\nThe pair could meet again in the Breeders' Cup Ladies' Classic at Santa Anita, to which Mushka gained automatic entry with her win in the Spinster, a Breeders' Cup Challenge race. Mushka is probable to go on to the Ladies' Classic, said Bill Mott, who trains her for the Brushwood Stable of Elizabeth Moran. Mushka has made 10 of her 16 starts on turf, but now is 2 for 2 in synthetic-track races, and may prefer artificial surfaces to turf.\n"This is the best she's run for me," said Desormeaux.\nProviso also could wind up in the Ladies' Classic, said Juddmonte farm manager Garrett O'Rourke.