Queen Mary runner-up Shumoos was taken off her feet in the early stages and was over 10 lengths behind the pace-setting Trinniberg.
Rafael Bejarano looked confident on Bob Baffert’s Secret Circle and took up the running entering the straight.
That was when Shumoos hit top gear, slicing through the field against the rail, and looked to be catching the leader, especially when Secret Circle drifted into the middle of the track.
However, Bejarano managed to keep his mount up to the task as the meeting got off to a thrilling start.
Baffert, celebrating his eighth Breeders’ Cup win, said: “I was worried because he looked lost out there but he’s so extremely talented.
“We’ll bring him back next year maybe and stretch him out (in trip) if we can.
“If he didn’t run well I was going to have a bad weekend, and I told everybody that, so this is a good start.”
Aidan O’Brien’s Misty For Me came from way off the pace to finish a close third behind shock winner Perfect Shirl and Nahrain in the Breeders’ Cup Filly & Mare Turf.
Ridden by Ryan Moore, she sat at the back of the pack for most of the journey before being asked to make her move approaching the home turn.
With no option but to make her effort wide, she tried to come right round the entire field. Making giant strides in the straight, she was beaten just three quarters of a length and a nose by Roger Attfield’s Perfect Shirl, who was recording her first victory since a debut success back in July of last year.
John Gosden’s Elusive Kate was well beaten as Stephanie’s Kitten finished with a late flourish to win the Breeders’ Cup Juvenile Fillies Turf.
Gosden’s youngster was sent off favourite after winning the Prix Marcel Boussac at Longchamp, but from her wide draw William Buick could never get any cover and was one of the first horses beaten. Stopshoppingmaria made a bold bid but Stephanie’s Kitten got a great run up the rail and showed a fantastic turn of foot to win going away.