Cirrus Des Aigles gained his first domestic Group One win in the Prix Ganay at Longchamp.
Corine Barande-Barbe's six-year-old was a warm favourite for the Paris contest and was able to secure his first victory at the very top level in France with little difficulty.
The Even Top gelding was only third in the corresponding race 12 months ago but has since added victories in the Qipco Champion Stakes at Ascot, and most recently, the Dubai Sheema Classic at Meydan.
Here he dictated his own pace out in front and quickened nicely clear in the final two furlongs under Olivier Peslier to win in impressive fashion.
Alain De Royer-Dupre's French Derby winner Reliable Man was sent off the second favourite but he could only finish third, a place behind his stablemate filly Giofra.
Michael Bell's Wigmore Hall was the sole British challenger and finished out of the frame under Hayley Turner.
Barande-Barbe said: "We are very proud of him - he is a magic horse. "We have been waiting for that (first Group One in France) for a long time and he won so easily.
"Olivier gave him a very good ride. Now the horse knows more about racing, you can just let him do what he wants.
"It was a fantastic performance and we are all delighted."
Cirrus Des Aigles could return to British shores this summer, with the Coronation Cup at Epsom and the Prince Of Wales's Stakes at Royal Ascot possible options before he defends his Champion Stakes crown.
"We will consider what to do next. There is the Coronation Cup, Royal Ascot, the Grand Prix de Saint-Cloud and Singapore to consider," said the trainer.
"He has not had a hard race today and we will make a decision about the next place to go with him.
"It would be great to go back to Ascot at the end of the season for the Champion Stakes again."
There were two other Group races on the Longchamp card, with Trois Lunes recording a narrow victory in the Prix Vanteaux and Usuelo running out a comfortable winner of the Prix De Barbeville.