Les Arcs shattered Takeover Target's hopes of a famous double when he landed the showpiece Golden Jubilee Stakes on the fifth and final day of Royal Ascot.
Les Arcs wins the Golden Jubilee Stakes at Royal Ascot
The Tim Pitt-trained Les Arcs (33-1) hit the front one furlong out and hung on by a neck as Balthazaar's Gift (50-1) came from nowhere to challenge.
Australia's 7-2 favourite Takeover Target was two lengths back in third.
The Joe Janiak-trained Takeover Target was bidding to add the race to the King's Stand Stakes he won on Tuesday.
Les Arcs was 11th behind Takeover Target in Tuesday's five-furlong Group Two feature but excelled over the extra furlong in Saturday's Group One race.
John gave him a great ride but it was the longest furlong in my life
Les Arcs' trainer Tim Pitt
Egan, who now has two Royal Ascot victories to his name this week, said: "I heard on the commentary there was one (Balthazaar's Gift) coming up and I panicked slightly that he was going to come and do me.
"He's a fantastic horse and was useful over a mile and a quarter.
"We used to think he was a bit quirky because he never got there but five, six and even seven furlongs seem to suit him a lot better.
"Tim's got a great team and I'm sure he'll go from strength to strength."
Pitt added: "This guy (Les Arcs) put us on the map with a good winter. John gave him a great ride but it was the longest furlong in my life.
"This guy has got a lot of natural speed but when he kept going up and up the handicap there's only so many places he can be entered up.
"He's in the July Cup and that's where we'll probably go next."
Janiak, the part-time taxi driver from Canberra in Australia, said of Takeover Target, said: "I'm absolutely rapped with that.
"He tried his hardest and six is definitely his best trip - I couldn't have expected much more than that.
"We can't be disappointed but probably Tuesday took it's toll in the last furlong.
"I'm so pleased I came over - I would have regretted it for the rest of my life if I hadn't."
Meanwhile, the Sir Michael Stoute-trained Maraahel edged out stablemate Mountain High to win the Group Two Hardwicke Stakes over one mile four furlongs, with Enforcer third.
In the 28-runner Wokingham Stakes, Baltic King surged on the stand rail to pip 5-1 favourite Firenze inside the final furlong in one of the biggest betting races of the year.
Veteran Bahamian Pirate, David Nicholls' 11-year-old, got up for third with Borderlescott finishing a staying-on fourth.
1625 - Wokingham Stakes (6f)
1 Baltic King (J Fortune) 10-1
2 Firenze (J Spencer) 5-1f
3 Bahamian Pirate (E Ahern) 33-1
4 Borderlescott (R Ffrench) 14-1
28 ran. Dist: 1½, 1½
1545 - Golden Jubilee Stakes (Group One) (6f)
1 Les Arcs (J Egan) 33-1
2 Balthazaar's Gift (J Spencer) 50-1
3 Takeover Target (J Ford) 7-2f
18 ran. Dist: nk, 2l
1505 - Hardwicke Stakes (Group Two) (1m 4f)
1 Maraahel (R Hills) 9-2
2 Mountain High (K Fallon) 7-2f
3 Enforcer (K McEvoy) 8-1