Euchen Glen caused a major surprise in the rearranged Betsafe Cumberland Lodge Stakes, with Logician losing his unbeaten record in finishing a disappointing last of four at York.
Back at the scene of his finest hour, Euchen Glen had won the John Smith’s Cup on the Knavesmire in 2018.
Injury then kept him off the track for over 700 days, but he had claimed victory in a valuable contest at Haydock last month.
Even so, he was sent off at 18-1 against last year’s St Leger winner, who himself had overcome a year on the sidelines to win on his return at Doncaster.
Logician was the 1-3 favourite for the Group Three transferred from Ascot’s waterlogged meeting last weekend, and Martin Harley seemed happy enough on John Gosden’s charge until passing the three-furlong marker.
Harley wanted to grab the rail on the previously-unbeaten Frankel colt, but was unable to do so before Paul Mulrennan and Euchen Glen, who were relentless in front.
Harley had a brief look down on Logician and ultimately allowed him to come home in his own time.
It was left to Desert Encounter to challenge Euchen Glen, but Jim Goldie’s favourite won by half a length.
Goldie said: “I would say that was a masterclass in riding. As Baldrick would say, we had a cunning plan and I can’t believe how well it went.
“We thought we’d try to bring the field across to the rail as it complicates things, it gives the jockeys a decision to make and it worked a treat.
“To take a scalp like that is great. Some thought it pie in the sky against a superstar, but Paul was up for it and so was I.
“The horse we beat is probably rated similar to us and it looks like the favourite hasn’t turned up.
“Our horse is a superstar and Paul gets a great tune out of him.”
He added: “He’s actually in the Balmoral over a mile on Champions Day. He’ll go on the ground so we’ll just see how he is. I don’t think there’s much else.”
Teddy Grimthorpe, racing manager for Logician’s owner, Khalid Abdullah, said: “The horse pulled up sound and obviously he’ll be checked out when he gets back.
“From the point of view that he is sound, that’s a bonus, but obviously there must be something to explain it.”