(CNN) -- The Queen's hopes of marking her Diamond Jubilee with a win at Royal Ascot were dashed when her horse, Carlton House, was beaten by two-and-a-quarter lengths by So You Think in the showpiece Prince of Wales Stakes on Wednesday.
The victory marked redemption for the Aiden O'Brien-trained six-year-old. Runner-up in this race last year to the ill-fated Rewilding, the New Zealand-bred horse has traveled the globe in search of an elusive 10th Group 1 victory.
The dual Cox Plate winner could be considered to be the horse with the biggest carbon footprint in racing, having tried his luck in Australia, France, the U.S. and Dubai.
He is now expected to take a well-deserved retirement to stud having passed the £5 million ($7.87m) prize money barrier.
The Queen, dressed in pink for the second day of Royal Ascot, had watched Carlton House parade before the race and exchanged a few words with Sheikh Mohammed of Dubai, who gifted Carlton House to the Queen as a yearling.
One of the best-known owners and breeders of racehorses in the country, the Queen has not had a Group 1 winner in Britain since Dunfermline captured the St Ledger Stakes in her Silver Jubilee year, 1977.