Top Trip sprang a surprise when winning the Group Two Prix Hocquart at Longchamp for Francois Doumen and Thomas Huet.
Joseph O'Brien set out to make all the running aboard Athens but he was overhauled well over a furlong out and faded to finish fifth.
Sir Jade was first to take the leader's measure but he couldn't sustain his charge and was reeled-in by odds-on favourite Masterstroke.
However it was hard work for Andre Fabre's charge and he had nothing in reserve to repel the late thrust of Top Trip who burst between horses to win comfortably.
Doumen said: "This is a very progressive horse. He has an amazing temperament and physically he is still progressing. He is very cool, very relaxed, and he shows a lot of courage.
"He came through without Thomas (Huet) ever picking up the stick. It's a shame my wife isn't here as she bred him."
As to Athens, who was eventually fifth, trainer Aidan O'Brien said: "He ran well. In an ideal world he prefer a lead, but he wasn't beaten that far. They were all together, and finished within a couple of lengths together. He won't mind going further, he'll stay further."