Unbeaten Australian mare Black Caviar won by only a head to secure a dramatic 22nd career victory in the Diamond Jubilee Stakes at Royal Ascot.
Jockey Luke Nolen appeared to relax in the lead on the 1-6 favourite in the closing stages and narrowly held on from Moonlight Cloud (5-1) with 40-1 shot Restiadargent a neck further back in third.
Six-year-old Black Caviar, running outside her homeland for the first time after a 30-hour flight to the UK earlier this month, had cruised to the front with two furlongs remaining.
But there were nervous moments for trainer Peter Moody and Black Caviar's huge band of supporters before a photo finish confirmed the mare had won.
And Moody suggested she could be retired if she does not show her usual sparkle when she returns home.
"This was always going to be the greatest risk of her career and, for the last five or six runs, we've been prepared to accept it might be her last," he said.
"Hopefully, that's not the case today, but if she's as tired and worn out when she gets home, she may have graced the track for a final time."
Jockey Nolen eased up on Black Caviar in the closing stages of the race, and he blames himself for the ride.
"I underestimated the testing track of Ascot," he admitted. "She'd had enough and that big engine throttled right down.
"It's unfortunate, because we're going to talk more about my brain failure than the horse's fantastic effort.
"We won, but it may have overshadowed what was a fantastic effort by the horse. We got away with it."
Thirteen horses lined up for the big race after Hitchens was declared a non-runner, and Black Caviar broke cleanly from the widest draw in stall 15.
Frankie Dettori made the early running on Soul, but the Australian mare was handily placed in third before making what looked like a decisive move to the front.
As she went clear, a straightforward victory looked assured before the challengers closed in as the line approached.
"You've only got to win by a quarter of an inch - we got the job done," said trainer Moody.
"We never expect dominance - we never ask her for dominance - we are extremely proud of her.
"I'm an extremely proud Aussie. It's very fitting that it's with a horse like this."
Black Caviar, who became the race's first odds-on winner since Mountain Call in 1968, is a hugely popular figure in Australia where she is the most famous horse to have raced since the legendary Phar Lap in the 1930s.
Thousands of Aussie fans, many sporting the horse's colours of salmon with black spots, let out cheers of relief as the result was called.
The mare is ranked second in the world behind Frankel, who won the Queen Anne Stakes by 11 lengths at Ascot on Tuesday.
She will now return home, rather than competing in the July Cup at Newmarket - where she has been stabled during her time in the UK.
"We'll get her home now and it's all about looking after her," added Moody.
"She's never let us down, but she is a six-year-old and isn't going to improve."