Gregorian could be pitched in against formidable American challenger Animal Kingdom at Royal Ascot after securing a deserved return to the winner's enclosure in the Diomed Stakes at Epsom.

Already the winner of a Kentucky Derby in his homeland, Animal Kingdom produced a devastating display in the Dubai World Cup in March and promises to be one of the star attractions of this year's Royal meeting as he struts his stuff in the Queen Anne Stakes over the straight mile.

While Gregorian will have to raise his game significantly to trouble the trans-Atlantic raider on June 18, trainer John Gosden can at least consider the Group One assignment after his charge turned in a fine Group Three triumph.

The 3-1 joint favourite took over the running from market rival Producer at the top of the home straight and despite looking slightly unbalanced on the cambered track, he was good value for his winning margin of a length and a half.

Penitent finished well to fill the runner-up spot.

Gosden said: "I couldn't be more pleased for the horse, he thoroughly deserves a Group-race victory.

"He is in the Queen Anne, but there's a certain horse called Animal Kingdom in there and quite frankly he's an imperious horse. The fact that he's here is extraordinary.

"We're really lucky that they've brought him from America to be here, but we could run against him if we get rainfall, he wouldn't run on firm (ground).

"It would be lovely to run as someone has to be second, third, fourth and fifth."