Aidan O'Brien won his first Prix Rothschild at Deauville on Sunday as Roly Poly won her second consecutive Group One.
Ryan Moore sat the daughter of War Front in a prominent position just off the lead set by Usherette, with last year's winner and favourite Qemah held up in the rear by Cristian Demuro.
As Usherette started to wilt towards the stands' rail Roly Poly took up the running with Qemah making her challenge right on the inside.
Jean-Claude Rouget's filly couldn't reel in the leaders, though, finishing out of the frame as Roly Poly hung on for a narrow success over Via Ravenna and Siyoushake.
It was the second Group One win in as many races for Roly Poly, as she won the Falmouth Stakes at Newmarket's July Festival on her previous start.
Fahey second as Tantheem dazzles
Later on the card Richard Fahey's Darkanna finished second in the Group Three Prix de Cabourg as Freddie Head's Tantheem powered clear for an easy victory.
Darkanna was seventh behind Heartache in the Queen Mary at Royal Ascot before finishing seventh in the Duchess Of Cambridge Stakes last time, but she enjoyed her trip to Deauville by running on for second behind a very impressive winner.
Tantheem only won her maiden on the Deauville polytrack last time, but she relished the return to turf with a ready success under Mickael Barzalona.