Luke Nolen riding Black Caviar (Salmon Black spots) win the Diamond Jubilee Stakes during day five of Royal Ascot at Ascot racecourse on June 23, 2012 in Ascot, England.

Black Caviar, by a short head, sealed her status as the queen of thoroughbred sprint racing as she swept to her 22nd consecutive victory in the Group One Diamond Jubilee Stakes at Royal Ascot.

The champion horse put on a thrilling show, for the Queen herself, as she became the first mare in 27 years to win the race by a scant few inches over second favourite, French horse, Moonlight Cloud.

Jockey Luke Nolen rode confidently near the line and held his whip as the French challenger made the race much closer than trainer Peter Moody ever expected.

"I underestimated the testing track of Ascot, I got into her late, she had nothing left and the big engine throttled right down," said Nolen immediately following the race. "It's quite unfortunate because it's going to overshadow what was a very good win."

"They are going to talk more about my brain fade that horse's fantastic effort."

Melbourne fans watching in Federation square briefly held their breaths as a photo finish was required to confirm the super mare had held off the bold European challenge ridden by Thierry Jarnet.

A second French runner Restiadargent ran a close third.

Trainer Moody was very circumspect following the race, hinting the great horse may have run her last race.

"Black Caviar was not 100 per cent in the race. We'll look at her when we get home and she might be retired," said Moody.

Moments after the race, Moody had dismissed any ideas he was disappointed with the distance of the winning margin saying, " you only have to win by a quarter of an inch and that's what were prepared to come here and win by and we've got the job done."

The Queen and Prince Phillip arrive at Royal Ascot. Photo: Getty Images

Australia's High Commission in London received unprecedented interest from Australian citizens in its ballot for 400 Royal Enclosure passes on Saturday, which a spokesman attributed to Black Caviar's run.

Royal Ascot public affairs spokesman Nick Smith said while Australian attendance has been high in the past for the likes of Miss Andretti and Scenic Blast, 2012 is a standout.