Australian Bloodstock-owned Turfdonna gave trainer Andreas Wohler his third domestic classic winner in 2015 with victory in Sunday's Group I Preis der Diana (2200m) at Dusseldorf.
Having won the 1000 and 2000 Guineas double with Karpino and Full Rose, Wohler saddled three in the German equivalent of the Oaks.
Tracking the pace set by Let's Dance, Turfdonna was shaken up by Eduardo Pedroza 400m out and reached the lead inside the final 100m to hold off the late rally from Nightflower and score by three-quarters of a length.
Amona finished a further 1 1/4-lengths away third with favourite Lovelyn finishing ninth under Frankie Dettori and never a factor.
Wohler took over the training of Turfdonna from Roland Dzubasz following her private purchase in the spring and told the Racing Post he was unsure of future plans.
"The absolute limit for her in my opinion is probably 11 furlongs, so we are more likely to go down to ten furlongs rather than run over 12," Wohler said.
"She was a bit disappointing last time at Hamburg, but the better ground here was just what she wanted. Eddie (Pedroza) always had her in a perfect position and that is a major factor at this track."
It is the first stakes success for Turfdonna at her fourth race start and the second win in the race for Australian Bloodstock, who won in 2012 with Salomina.
You can see the race below, Turfdonna in the blue jacket, black and white check cap and second out of the home straight the first time.
