Address Unknown gave enthusiastic owner Dr Marwan Koukash his second victory in the StanJames.com Chester Cup.
Koukash had four in the race and Address Unknown (12-1) did the business in his first start since joining Richard Fahey.
The Malton trainer also saddled runner-up Ingleby Spirit, who was half a length adrift at the line.
Tominator (11-1) was third and joint-top weight Simenon (16-1) fourth.
Winning jockey Jamie Spencer said: "He was very brave. He did really well with Ian Williams last year and the race went very smoothly.
"It's good for Dr Koukash, as well."
Koukash said: "I'm absolutely delighted.
"When we lost Montaser (non-runner), I thought that was my luck gone, but Jamie gave this horse a fantastic ride.
"Richard has done extremely well with the horse over the past couple of months.
"This is a good start for me for the meeting.
"I'm over the moon. I've been in racing five or six years and the only thing I wanted to do was win the (Chester) Cup again.
"Winning the Cup introduced me to racing and to do it again is absolutely wonderful."