Marcel recorded a shock win in the final Group One of the flat season, the Racing Post Trophy at Doncaster.
Unbeaten odds-on favourite Foundation, ridden by Frankie Dettori, found himself boxed in during the mile race and could only finish third.
It was a third successive victory in the race for jockey Andrea Atzeni, who moved to the outside to guide 33-1 shot Marcel home by a length-and-a-half.
Johannes Vermeer finished second in the field of seven.
BBC Horse Racing correspondent Cornelius Lysaght:
“What a nightmare for Frankie Dettori. At the end of a dream year when practically nothing has gone wrong for him, nothing much went right here as Dettori and the previously unbeaten Foundation were stuck behind a “wall” of horses when needing space to mount a challenge.
That said, Marcel might have won anyway. He was quite impressive for the ever-popular – but quieter than he used to be – Peter Chapple-Hyam, the winner of this with subsequent Derby winner Authorized (2006); Epsom is sure to be the target for Marcel too.”
Dettori was tracking second favourite Deauville, one of three Aiden O’Brien horses in the race, but by the time he found clear ground in the closing stages he was was left with too much to do.
Atzeni, who rode Kingston Hill and Elm Park to victory in the previous two years, said: “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.”
It was also a third success in the coveted race for trainer Peter Chapple-Hyam, after Commander Collins in 1998 and Authorized in 2006.
“Authorized won this at a big price and I did say Marcel was no Authorized, but that was because this lad had already won a maiden,” a jubilant Chapple-Hyam said.
“Even though I don’t have many good horses, you know when a good one comes along.
“He obviously goes on any ground and will be better next year when he’s stronger.
“I see him as a French Derby type, I’d be worried about him staying further (12 furlongs). If I get my way, he’ll be in my favourite race, the Dante, but if he shows enough speed before then he could go for the Guineas.”
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