Australia's attempt to maintain its international sprinting dominance fell flat at Royal Ascot on Tuesday with the failure of Shamexpress in the King's Stand Stakes (1000m).

After looming as a winning chance 200m out Shamexpress found little in the run to the line, dropping out to finish a distant ninth.

For trainer Danny O'Brien the performance came as a shock and a disappointment.

"He seemed to travel well, he was aeon a good position but he didn't go on with it," O'Brien said.

"When I expected him to put in his bid, he had reached the end of it.

"We'll have to assess him and see what we're going to do."

Connections had hoped to run Shamexpress in the July Cup at Newmarket and then the Nunthorpe Stakes at York.

But plans are now likely to be revised.

Shamexpress finished a long way behind the Irish-owned and trained runner Sole Power, a noted local speedster who won by a neck from the South African sprint Shea Shea.

Earlier, the Australian-owned Dubai World Cup winner Animal Kingdom, proved an even more notable failure in the Group One Queen Anne Stakes (1600m).

The 5/4 favourite raced in midfield to the 300m from which point he went backwards and finish a dismal 11th.

Trained in the United States by Englishman Graham Motion, Animal Kingdom came to the Royal meeting as one of the hottest favourites for the week.

But the short odds proved unjustified.

"At the half mile pole the jockey started to ask him to run and there wasn't much there," Motion said.

"I would say that is probably it for the horse."

Australian breeder John Messara bought a half share in Animal Kingdom, who is also a Kentucky Derby winner, before this horse won the World Cup in March.

He will now be retired to stand at Messara's Arrowfield Stud in the Hunter Valley in NSW.