The globetrotting Rebel’s Romance added Royal Ascot to an impressive CV which has brought big victories in the United States, Dubai and Hong Kong.
At seven years old, he is oldest winner of the race for more than a century and adds to career earnings of more than £10m.
“We had one shot, one roll of the the dice left and what a partner. He’s a dream horse – I’m blessed,” said Buick.
“We gel together – he’s my best friend.”
The 6-4 favourite finished clear of Al Riffa with third place going to Ghostwriter, who was bought by Kia Joorabchian’s Amo Racing for £2m this week.
In a week when temperatures reached 30C, Humidity was an aptly named winner of the Chesham Stakes.
The 4-1 shot, under James Doyle for trainer Andrew Balding, provided a fourth winner of the week for owners Wathnan Racing.
A brother of 2022 victor Holloway Boy, Humidity was bought by the Emir of Qatar’s Wathnan team following a winning Newbury debut in the Cheveley Park Stud colours.