Roger Varian is dreaming of Classic success next year after Kingston Hill continued the Newmarket trainer's love affair with Doncaster by winning the Racing Post Trophy, Britain's final Group One race of the season.

His first ever runner, Eton Forever, was a winner there on April 2, 2011 after Varian took over the reins at Kremlin House stables when the late Michael Jarvis retired.

Kingston Hill only made his debut five weeks ago and after winning the Group Three Autumn Stakes at Newmarket at his second start, Varian and owner Paul Smith took the decision pay the STG17,500 ($A29,635) late entry fee into the prestigious juvenile race.

It was a brave move by Smith, who is the son of Coolmore's Derrick Smith, co-owner of runner-up Johann Strauss.

Racing in mid-division through the early stages, Kingston Hill was asked to quicken more than a furlong (200m) out by Andrea Atzeni and the response was immediate.

The colt lengthened stride in the closing stages, beating Johann Strauss by 4-1/2 lengths.

"We were looking forward to what improvement there was to come from him and he's the first colt to win to win a Group One for us. It's been with fillies before," Varian said.

"We'll have to see how he winters and what he's like in the spring. People have said is he a 10-furlong, mile-and-a-half horse, but he has the pace for a mile and travels so well.

"He has good acceleration and will be in everything. We'll have a good eye on the Guineas."

Ladbrokes cut Kingston Hill to 8-1 from 20-1 for the 2000 Guineas, while Paddy Power went 10-1 about his chance in the Guineas and Derby.