Henry Cecil's Chachamaidee lifted Group One honours at Leopardstown as Duntle lost the Coolmore Fusaichi Pegasus Matron Stakes in the stewards' room.
Winner of the Sandringham Handicap at Royal Ascot and again in the Desmond Stakes at this track last month, Wayne Lordan had to sit and suffer on the David Wachman-trained Duntle waiting for the gaps to come.
Emulous had just got on top of long-time leader Laugh Out Loud but was mown down late by Duntle (7-2) once she got in the clear, although there was some scrimmaging in the process of her doing so.
Chachamaidee (11-2) was the other to finish with a rattle on the outside under Tom Queally, getting a bump on the way as a result of what the stewards deemed was Duntle's manoeuvre, but the Wachman filly got the verdict on the line.
However, what turned into a lengthy stewards' inquiry was immediately called and just before the next race it was announced the placings had been reversed.
Second in the Windsor Forest at Royal Ascot and winner of the Lennox Stakes at Glorious Goodwood, Chachamaidee's last start had seen her beaten less than two lengths in the Celebration Mile.
Last season she was second to Sahpresa in the Group One Sun Chariot Stakes at Newmarket.
Queally said: "You're always biased towards your own animal. I felt quite strongly though and expressed my views (to the stewards).
"It's not the way you like to win but it was a well-deserved win for Chachamaidee.
"It wasn't an easy decision for anyone (the stewards) but I think they've got it right here.
"I didn't know if I'd won or not (on the line) - it was that tight.
"I've spoken to Sir Henry's wife, Jane, they are all delighted and the (Group One) flag is flying at Warren Place."
Battle Of Marengo (9-10 favourite) looks set for better things after making all in style to claim the ICON Breeders' Cup Juvenile Turf Trial Stakes for Aidan O'Brien in the hands of his son, Joseph.
A very easy winner of a Gowran maiden last month, the Galileo colt stepped up to Listed company with ease, despite a slipped saddle, never being asked a serious question in holding the running-on Jim Bolger newcomer Trading Leather in what looked a good race.
O'Brien senior said: "He'll step up now and we could look at something like the Beresford or the Racing Post (Trophy).
"He could be a Derby horse in time, but that's still a long way away."
Stan James went 16-1 about his Investec Derby claims with Paddy Power 25-1.
Big Break is another in the picture for a step up in class after impressing in the Irish Stallion Farms European Breeders Fund Fillies Maiden.
Third on her debut when sent off favourite at Galway, the Dermot Weld-trained full-sister to Famous Name showed the benefit of that experience, going clear at the top of the straight and never looking in danger thereafter.
Weld said of the 9-10 winner, who got a 25-1 quote for the 1000 Guineas from Stan James: "Things didn't go her way at Galway first time out but she showed just how good she is today.
"If things go to plan I feel she may progress into an English 1000 Guineas prospect."
Alla Speranza (10-1) finished best of all on the outside to claim the KPMG Enterprise Stakes for Bolger and jockey Kevin Manning.
Bolger said: "I'm very happy now to have won a race of that calibre with her. She's been knocking on the door so she's entitled to get her head in front.
"She put up a good performance in the English 1000 Guineas but maybe we ran her back a bit soon after that and then it took her a while to get over it.
"She's been in good form now for the last couple of weeks. The ground suits her fine."