The Frankie Dettori-ridden Nahrain narrowly missed out as Canadian outsider Perfect Shirl took the Breeders' Cup Filly & Mare Turf.
Perfect Shirl took advantage of the favourite Stacellita being hemmed in to gallop on strongly for victory.
Irish filly Misty For Me finished late and fast after stumbling out of the stalls to claim third place.
Nahrain's trainer Roger Varian said: "I'm frustrated not to win but super, super happy with her run."
Derrick Smith, a partner in Coolmore Stud, and owner of the Aidan O'Brien-trained Misty For Me, added: "I'd like to think she would have gone very close but for that [stumble]."
On a generally disappointing night for Europe, in other races at flat racing's self-styled 'world championships', the best finishing position was achieved by the Brian Meehan-trained filly Shumoos, runner-up behind Secret Circle in the Juvenile Sprint.
Big British hope Elusive Katie never really featured behind narrow winner Stephanie's Kitten in the Juvenile Fillies (Turf) race in which Irish challenger Up was a creditable fourth.
In the race staged for two-year-old fillies on a dirt surface, the hugely impressive My Miss Aurelia, ridden by Corey Nakatani, retained her unbeaten record, now four from four, in great style.
Royal Delta, storming winner of the concluding Ladies Classic, paid a big compliment to Havre de Grace, second favourite for Saturday's Breeders' Cup Classic race, having been beaten by eight lengths by her when they met last month.
In Saturday's races,
record-breaking French mare Goldikova and Strong Suit (Breeders' Cup Mile)
and Ireland's So You Think (Breeders' Cup Classic) lead the European charge.
The Breeders' Cup Mile, among the highlights of the self-styled "world championships" of Flat racing which start on Friday, is at 2207 GMT on Saturday, 5 November, screened live on ATR Channel