British challenger Wuheida finished an honourable third in the German Oaks at Dusseldorf.
Charlie Appleby's daughter of Dubawi won each of her two starts as a juvenile, including the Group One Prix Marcel Boussac at Chantilly.
She returned from nine-month absence in the Falmouth Stakes at Newmarket a shade over three weeks ago and ran a fine race to fill the runner-up spot behind Aidan O'Brien's subsequent Prix Rothschild scorer Roly Poly.
Appleby had hoped to step his filly up in distance in the Nassau Stakes at Goodwood but after being withdrawn on account of the rain-softened ground, she instead journeyed across Europe for the 159th Henkel-Preis der Diana.
Stepping up to a mile and three furlongs, Wuheida was a hot favourite in the hands of William Buick, but had to make do with minor honours behind Peter Schiergen's Lacazar.
The Andreas Wohler-trained Megera, ridden by champion jockey Jim Crowley, split the pair in second.