Cavalryman powered to victory under Kieren Fallon in the Goodwood Cup on Thursday, ahead of Ahzeemah and last year's winner Brown Panther.
The eight-year-old, who took the lead two furlongs out, became the first horse of that age to win the event since Persian Punch in 2001.
Fallon said: "He's a tough horse. It's a very difficult race to win but he's gone from strength to strength."
The Queen's horse Estimate, the 2-1 favourite, faded badly in the straight.
It was the five-year-old mare's first race back since testing positive for morphine after the Ascot Gold Cup last month.
Cavalryman held off a late surge from Ahzeemah to win by a neck at the line.
Trainer Saeed bin Suroor said: "He's a good fighter, he goes on any ground and he has improved with age.
"He's a stayer and a mile and three-quarters and two miles are the best trip for him.
"He showed some turn of foot and now we take him to York for the two-mile race, the Lonsdale. And at the end of the season I will talk to Sheikh Mohammed, but it could be the Melbourne Cup."