Marcel sprang a 33-1 shock in the Racing Post Trophy to give Andrea Atzeni a third successive victory in the Group One for two-year-olds at Doncaster.
The Peter Chapple-Hyam-trained colt, who had won a Newcastle maiden on his previous start, came with a trouble-free run on the outside to turn over the better-fancied horses.
Port Douglas, one of three Aidan O'Brien horses in a seven-runner field, set the pace with his stablemates Deauville and Johannes Vermeer always handy.
Frankie Dettori gave his mount Foundation plenty of cover but could not get a run when the race unfolded and Atzeni took advantage to follow up his wins on Kingston Hill and Elm Park in the two previous renewals of this prestigious race.
Once the 10-11 favourite Foundation got a run it was too late as Marcel had flown. Johannes Vermeer stuck on for second, beaten a length and a half by the winner.
Atzeni said afterwards: "It's great for Peter. I was going to follow Frankie, but it got a bit tight so I thought I'd go round. "As soon as I pulled him out, he picked up. "He was very good today. He quickened up well on that ground and he won going away.
"I'm delighted to ride a Group One winner and mainly for Peter. He's a great trainer."
