Kingston Hill stayed on best of all to lift the Ladbrokes St Leger at Doncaster.

The 9-4 favourite had been a doubt for the race due to the ground, but the Derby runner-up was given a fine waiting ride by Andrea Atzeni to deliver both his and trainer Roger Varian's first British Classic.

Just as Epsom third Romsdal moved to strike for Leger specialist John Gosden, Kingston Hill began his charge, and although he brushed past eventual third Snow Sky, he was a length and a quarter on top at the post.

Atzeni said: "I don't know what to say, it's a dream really. It's unbelievable. I rode him like the best horse in the race, he travelled beautifully. He's so laid-back, he goes to sleep. When I pulled him out he was always going to get there. He was just wandering about when he hit the front."

Aidan O'Brien's raider Granddukeoftuscany cut out the running for three-quarters of the way, followed by Forever Now, Hartnell and Romsdal. As his challenge faded inside the last half-mile, Gosden's Forever Now and Frankie Dettori made the first move before he was swamped by the closing pack.

No horse had more left than Kingston Hill, who had competed in all three of the colts' Classics as he had started his year off with an eighth in the 2000 Guineas but was making his first appearance since finishing fourth in the Eclipse at the start of July.

Varian said: "I'm so pleased for the horse, for him to get the credit he deserves, for the owner Paul Smith and all the team at home, who work so hard. To win a Classic is just brilliant, brilliant.

"He looked a Classic horse at the start of the year and he's won a Classic. I think the long nights and the dew have helped with the ground and also today being overcast, but I think it was quicker than ideal for him."

Looking to future targets, Varian said: "First we have to get him home and see if he comes out of the race OK. He's not had a busy summer. Hopefully he's not finished this year. We'd have to consider the Arc if he came out of this OK. He's had a hard race today. He's got out to come of it well and we have to make sure he's 100 per cent."

Gosden, who had three runners in the race, headed by Romsdal, said: "They have all run well. No complaints. They have all run well."

Windshear was fourth and trainer Richard Hannon said: "He'll be a better horse next year. All he has done this year is grow and get stronger, so next year will be a big year for him. That could probably be it for this season for him."

There was drama before the start when Odeon was not allowed to compete, as he was still sporting the headgear he was only supposed to wear in the paddock.

"I didn't see that coming. I asked Mr Given (trainer) when will I take the hood off, he said leave it on as long as you can, if he's edgy take it off," jockey Graham Lee told Channel 4 Racing.

"I went to post and was going take it off before going in the stalls. Mr Barclay the starter said you can't run, you've got to take it off leaving the parade ring."