Donald McCain's Ile De Re beat stablemate Overturn in the StanJames.com Chester Cup.
The former Ian Williams-inmate (10/1) was having his first run for McCain but with the ground in his favour, Jim Crowley's mount managed to overhaul Overturn (7/1) in the final furlong.
The runner-up, with top-weight, tried to make all like he did last year for Eddie Ahern and was unfortunate to be reeled in so late in the day.
Mark Johnston's Gulf Of Naples (11/2 co-favourite) was third, with stablemate Eternal Heart (14/1) in fourth just ahead of Harrison's Cave (11/2 co-favourite) in fifth.
The other co-favourite Shubaat looked ill at ease on the track from an early stage, and may not have been done any favours by the flag start.
Crowley said: "He was being a bit fractious at the start but I managed to get a good position after a furlong and we got a good trip all the way round.
"He travelled nicely and he was loving the ground so I was pretty confident and I knew he'd keep going."
McCain said: "Ian Williams deserves a lot of the credit as he did a lot of the work and we've only had him a few weeks.
"It was a brave run from the old horse as well. I don't quite know how to feel as he's beaten everything bar the other one.
"I thought he'd win two furlongs out but the weight on that ground has taken its toll.
"We all have a huge affection for him in the yard because he's so tough.
"Overturn is in the Ascot Gold Cup as well as the Queen Alexandra and that race would suit him. I shall speak to Tim (Leslie, owner) but I expect he'll end up running in one of those races at Ascot.
"We'd thought of the Northumberland Plate for Ile De Re but if he doesn't win another race for us, it doesn't matter.
"Flat racing is not the be-all-and-end-all for us but we are lucky to have some smashing horses that can do a job for us."
Johnston was delighted with Gulf Of Naples' effort but felt the flag start had scuppered the chance of Eternal Heart.
He said "Gulf of Naples did start the widest of the field and presumably he's used quite a lot of horse to get as close as he did early," said Johnston.
"It was a smashing run.
"If Eternal Heart had got a good position he would have finished a lot closer.
"He was stuck right at the back and Joe (Fanning) said everything piled in on top of him and instead of the start helping us from his good draw, it has in fact cost him the race."