However, a lengthy stewards' inquiry eventually ruled that there was insufficient evidence to change the order of the finish and Stopchargingmaria, a 7-1 choice, improved to nine wins in 16 career starts.
Stellar Wind had to settle for second while Curalina, like Stopchargingmaria trained by Todd Pletcher, finished a further 3-1/2 lengths back in third.
"You're concerned anytime there is an inquiry or an objection, but I felt pretty comfortable watching the head-on that we were going to be OK," said Pletcher after celebrating his second win of the day.
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"Anytime to win a Breeders' Cup race it's extra special. I'm really happy for the connections (owner Kiki Courtelis of Town and Country Farms). It's their first Breeders' Cup and they're very excited."
Espinoza, who will be aboard favourite American Pharoah in Saturday's concluding showpiece $5 million Classic at Keeneland, praised Stellar Wind's gutsy run down the stretch.
"Turning for home, I was right next to Javier," Espinoza said of the three-year-old filly, a 9-1 choice. "I didn't want to get bumped. His horse went about six wide and I had to go with him.
"I was very close, but I didn't want to bump her. My filly really ran great. She showed a lot of fight."
Four-year-old filly Untapable, who won the 2014 Distaff by 1-1/4 lengths, was unable to defend her title on Friday after being scratched from the race earlier in the week due to a fever.
The Distaff, which highlighted the opening day's four-race card at the Breeders' Cup, was previously known as the Ladies' Classic.
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Ken Ferris)
