Slade Power claimed a summer sprint double by easing to victory in the July Cup at Newmarket.
Trained by Eddie Lynam, the 7-4 favourite won by a length and a half to add to his victory in the Diamond Jubilee at Royal Ascot.
Tropics, the 66-1 outsider, finished second with Gregorian third.
"He's really stepped forward this year and it is great for him to get a second Group 1," said Slade Power's jockey Wayne Lordan.
It could be Slade Power's last European race with new owners Sheikh Mohammed's Darley Stud, who bought him from the Power family this week, set to run him at the Melbourne Cup before a career as a stallion.
If it was to be Slade Power's last encounter on English soil it was certainly a fine farewell as Lordan saw him through a tricky field who had bunched into two groups.
"He's not keen but travels well in your hands," said Lordan. "I just looked at the other group and it all worked out well for me today."
Slade Power's stable mate Sole Power was pulled out of the six-furlong race due to the "dead, tacky" ground, according to Lynam.