Undrafted won the Diamond Jubilee Stakes for Frankie Dettori and American trainer Wesley Ward.
Ward is no stranger to success at the big meeting but all his previous winners had come in two-year-old races.
The final 100 yards turned into Australia versus America as Brazen Beau, who had ploughed a lone furrow throughout from his draw in stall 15, looked to be taking the prize Down Under.
However, Dettori, who could not have been further away from the Australian in terms of track position, made his move right round the outside of the field and prevailed by half a length.
Undrafted (14-1) was having his second run in England having finished fourth in the July Cup last summer.
Kevin Ryan’s horses continue to run well and Astaire ran out of his skin to claim third ahead of Music Master.
Dettori said: “Wesley is a good friend of mine and a big supporter so it gives me so much pleasure to win this for him.
“I didn’t want to kick too soon, he finishes so strongly.
“I haven’t got close to Ryan (Moore in terms of winners), but I’ve had three and that’s great.”
Ward said: “We had a rough night, my daughter got a touch of the Bell’s palsy so we were in hospital all night.
"Thankfully Derrick Smith (of Coolmore) got us fixed up with a great doctor and she was determined to be here today.
“This is unreal – it’s really special for my little girl.
“This is the biggest race I’ve ever won, including Breeders’ Cups and everything.
“He’s been training great, he really has, and Frankie just has the magic touch.
“He’s a magical guy, a real go-getter as we’d say.
“It would have been easy to have been closer to the pace but he came with a real late run.
“I don’t know about the July Cup, we’ll have a think about everything.”
Suits You held on grimly to deny Ryan Moore another winner on Ballydoyle in the opening Chesham Stakes.
Trained by Eoghan O’Neill, an Irishman who is now based in France but used to train in Britain, the son of Youmzain had won his only previous start at Maisons-Laffitte.
The race began in earnest inside the final furlong as Sixth Sense began to weaken and Suits You (14-1) hit the front.
However, Moore started to get a real tune out of the favourite Ballydoyle and the result had seemed inevitable.
Suits You stuck his neck out for Cristian Demuro, though, and the photo-finish went in his favour.
O’Neill said: “It’s brilliant. It’s really lovely. It’s great to come back and this our first Royal Ascot winner – it’s terrific.
“He’s very smart, he has been since February and I kept him for this race because as he’s by Youmzain, he’s gets in under the conditions of the race.
“It’s just wonderful to be here and to win.
“He will run in France next and then come back for the Royal Lodge.”
Mahsoob maintained his unbeaten record to give Paul Hanagan his first winner of the week in the Wolferton Handicap.
Having impressed at York last time out, he was sent off the 7-4 favourite to continue his progression.
Whereas in his two previous races this season he has overcome a poor draw, this time Hanagan was able to settle him just behind the pacesetting Fattsota and Sennockian Star.
The two leaders kicked early in the straight and for a moment Sennockian Star looked to have stolen a race-winning advantage, but John Gosden’s Coral-Eclipse entry quickened up to win by half a length with the fast-finishing Fire Fighting a head back in third.
Snow Sky made every yard of the running under a masterful ride from Pat Smullen to win the Hardwicke Stakes.
Winner of the Yorkshire Cup last time out, he was expected by many to find this trip a little on the short side and was sent off a 12-1 chance.
Michael Stoute, who has endured a miserable week to date, supplied three of the seven runners but hot favourite Telescope was expected to be his best chance of the winner.
Ryan Moore tracked Snow Sky on Telescope but having set a pretty sedate pace, Smullen then stole three lengths turning into the straight.
The rest were soon toiling and while Eagle Top stayed on to claim second from Postponed, he was three and three-quarter lengths back.
