Last season's Group 1 Falmouth Stakes winner returned to action with a fair fifth in the Group 2 Dahlia Stakes at Newmarket last-time-out.
Ralph Beckett's filly clearly improved plenty for that outing and showed a good attitude to get on top late to land a third career victory.
The pace was generous throughout with Roman Mist and Random Harvest cutting out the majority of the running. Ryan Moore looked happy on his position shortly after landing a third Epsom Derby with Potapova adopting a nice spot in third with Astral Beau, Shaara, and Prosperous Voyage rounding out the sextet.
The field panned out approaching the three-furlong pole and it looked to be anyone's race at that stage. Random Harvest struck the front entering the final furlong, but Ed Walker's filly was soon pressed on the outside with Frankie Dettori and Prosperous Voyage baring down. The daughter of Zoffany showed a good attitude to get on top in the closing stages to beat Random Harvest (22/1), who kept on resolutely for second, by three-quarters of a length. Astral Beau finished back in third for trainer Pam Sly and jockey Shane Kelly.
Following the success jockey Frankie Dettori announced that would be his last ride at Epsom.
The 52 year old Italian said: "I feel good. I'm relaxed. I'm a bit disappointed about the Derby, but to finish on a winner after over 30 years riding here is brilliant. I'm going to enjoy it and I'm going to eat a bit of grass from the winner's enclosure. I think I own it!
"I'm enjoying all of it. For most of the last few years I've been doing this there's been a tremendous amount of pressure, but I've got nothing to prove now. This is the end and I'm enjoying it, and that's why I'm riding so well.
"Prosperous Voyage always runs very forward, but she anticipated the jump and smacked her face in the gate.I was last, so it was Plan B then. It was meant to happen though as she's been making the running a few times and was probably sick of that, so it was good for her to follow some horses for once. She was very brave, as the gaps were tight. It was a good reference point for Royal Ascot."
On his Betfred Derby mount, Arrest (10th), Dettori added: The ground dried out and he found the track a bit uncomfortable. I knew my fate a long way out. It is what it is, but that's why Epsom is the ultimate test. You've got to be able to do everything."
Winning trainer Ralph Beckett added: "This will set her up nicely for the Duke Of Cambridge at Royal Ascot, and I've always felt she was better on a straight track. This is her first win for a while, so that's great.
