Space Blues produced a decisive turn of foot in the final furlong to open his Group One account in the Prix Maurice de Gheest at Deauville.
A winner at Listed, Group Three and Group Two level on his last three starts, the Godolphin-owned colt finally got his triumph at the top level in impressive fashion.
Trained by Charlie Appleby, the son of Dubawi had finished a close third to Advertise in this race 12 months ago, but has improved and now looks the finished article.
Although quickly out of the stalls from his rail draw, William Buick allowed others to set the pace as he gave his mount plenty of cover towards the rear.
Kevin Ryan’s Hello Youmzain soon grabbed the lead on the stands side, while the Clive Cox-trained Golden Horde was to the fore in the centre of the course. The latter was tracked by Godolphin’s other runner, Earthlight, from Andre Fabre’s stable.
There was a wide-open look to the race inside the final quarter-mile, as Hello Youmzain and Golden Horse tried to kick clear while Earthlight, the 10-11 favourite, ultimately flattered to deceive.
The gaps appeared for Space Blues (4-1), who burst through and stormed past his rivals in the final half-furlong to win by three-quarters of a length.
Hello Youmzain held on for second place, with Aidan O’Brien’s Lope Y Fernandez a head away in third.
Appleby said: “I’m delighted – this horse deserves a Group One.
“Last season as a three-year-old he was placed in two (Group Ones) and was a very consistent little horse.
“This year he’s been faultless and every time he’s been stepped up in grade he’s been winning more impressively. Today it all worked out well for him.
“William rode him with so much confidence. He said from halfway he knew he was going to win.”
Space Blues was given a quote of 5-1 for the Prix de la Foret at ParisLongchamp in October with Paddy Power, and Appleby added: “He’ll have a break now and we’ll aim for the Foret.”
Hollie Doyle notched up another big-race success when guiding Maystar to victory in the Prix Moonlight Cloud.
Riding with great confidence, she always had the Archie Watson-trained three-year-old up with the pace in the Listed heat over six furlongs.
Maystar responded to her urgings, battling on gamely to hold the challenge of Botch by half a length.
Doyle enjoyed her first Group success only last month and had a second on Extra Elusive in the Rose of Lancaster at Haydock on Saturday for her new retainer, owner Imad Al Sagar.
The Group Three Prix de Reux stayed in France through the Fabrice Chappet-trained Skyward.
Stephane Pasquier produced the four-year-old son of Camelot to assert in the closing stages and win by a length and a half from Sublimis, with Styledargent a short head back in third.
British raider Thundering Blue, trained by David Menuisier, was last of the eight runners after running too free on his first start since September.