Emirates Queen (20/1) relished the fast ground and step up in trip to land the bet365 Lancashire Oaks at Haydock Park.
The Luca Cumani-trained filly hasn't always appeared to be the most straightforward but she was on her best behaviour in the Group Two contest to spring a surprise.
Owned by Sheikh Mohammed Obaid Al Maktoum - who had earlier in the week dispensed with the services of Cumani's stable jockey Kieren Fallon - she challenged between horses to score a shade cosily from Moment In Time and the heavily backed Albasharah.
The lightly raced four-year-old daughter of Street Cry has rarely encountered the quick conditions that bring out the best of her but made the most of the opportunity that the recent dry spell had afforded her.
Stablemate Wannabe Loved and Midnight Soprano had cut out a steady gallop and few of the eight strong field could be ruled out in the straight.
Albasharah failed to pick up as her supporters would have hoped when asked to challenge on the outside of the weakening pacesetters and was immediately challenged by Moment In Time with Andrea Atzeni producing the eventual winner with a well-timed challenge.
Cumani's son and assistant, Matt, said: "I'm so happy. It's been such a long time coming. She really has matured but can still be a tricky, as she showed when she was reluctant to come back into the winner's enclosure.
"She's got a great pedigree. We've always thought a lot of her, with her looks and pedigree we thought maybe we were over-rating her but today she has showed her quality on the track.
"The Yorkshire Oaks would be the main target, but it's not until August 22, so it's still some time away."
Atzeni said: "I knew three out I was going to win. She loved the ground and wants that trip (mile and a half).
"They probably didn't go quick enough for me, but I got a lovely lead into the race and followed the Godolphin filly (Albasharah) through. She's a very nice filly and I think there's more to come from her."
It was a mixed day for Atzeni as he was banned for two days (July 20 and 21) for using his whip above the permitted level.
However he capped a memorable meeting by going on to complete a treble with wins on Ashaadd (9/2) in the bet365 Handicap for trainer Roger Varian and on the Ed Dunlop-trained Red Avenger (5/2) in the bet365 Handicap.