Aidan O'Brien celebrated the 50th juvenile success of his season when Royal Kingdom held on gamely for a half-length victory over the Clive Brittain-trained Best Of The Bests in yesterday's Group Two Serpentine Gallery Royal Lodge Stakes at Ascot.

The unbeaten two-year-old is now a 25 to 1 shot for next year's Epsom Derby after denying Brittain a famous double after his filly, Teggiano, won the Group One Meon Stud Fillies' Mile.

Teggiano, who maintained her position as 16 to 1 favourite for next year's 1,000 Guineas, was one of three successes for Frankie Dettori, including the impressive Dubai Millennium who quashed three opponents in the Queen Elizabeth 11 Stakes, the 4 to 9 favourite beating Almushtarak by six lengths.

And although yesterday's revised card went ahead after a 7 a.m. inspection, the heavy ground softened the impact of the colt's acceleration after Dettori, who had restrained him behind Gold Academy to the two pole, let his partner go.

"I think, from my small knowledge, he is the best we have had in Godolphin," opined Sheikh Mohammed of his colt, a non stayer in the Derby in the summer but winner of the Prix Jacques le Marois over a mile at Deauville last time out.

Dettori went on to complete his treble on Vicious Circle in the Ritz Club Stakes.

One expected to find conditions against him was Bold Edge, favoured by firm ground when winning the Cork And Orrery Stakes at the Royal Meeting in the summer.

Richard Hughes, riding fourth-placed stablemate Sampower Star, earned a three-day suspension for careless riding.