Kingston Hill has given trainer Roger Varian and jockey Andrea Atzeni a memorable first Classic win in the St Leger.

The victory came after Varian expressed concerns leading up to Saturday's race the ground at Doncaster would be too firm and he Kingston Hill might not run.

But connections took the plunge and Kingston Hill cruised past Romsdal and Snow Sky to take the final Classic of the British racing season.

For Varian it was a huge relief as earlier in the season he pulled him out of the Irish Derby because the ground was not to his liking.

"I am so pleased for the horse," Varian said. "For him to win a Classic is brilliant."

Atzeni, who has picked up the lucrative retainer with Qatar Racing for next season, was almost incapable of speech after crossing the line.

"I don't know what to say," he said. "It's a dream, it's unbelievable.

"He is so laid back. He just switches off and goes to sleep and then when you flick the switch he comes alive and has such a burst on him."

Smith, whose father Derrick has won many Classics through his association with trainer Aidan O'Brien and won the race last year with Fantastic Light, was overwhelmed by Atzeni's cool ride.

"Andrea rode a brilliant race he just put him to sleep and then woke him up with perfect timing," Smith said.

"My dad won this last year and he came to watch today. It is a very proud moment."

His delight was in stark contrast to the connections of Odeon who was disqualified as he went down to the start with a hood over his head which was termed "unauthorised headgear", although he had been allowed to wear it in the parade.

"James Given (the trainer) said to keep it on as long as possible," jockey Graham Lee said.

"I was going to take it off before entering the stalls but the starter told me on arriving down at the stalls that it was illegal and the horse was disqualified."