The son of Candy Ride, who carries the colours of Qatar Racing, has shown promise at home and showed a professional attitude throughout.
He was smartly away from the stalls under Jamie Spencer and raced keenly on the heels of the leaders.
The leader, Amber Isle, kicked off the turn but Jamie had that move covered and went in pursuit.
Knavery showed a good turn of foot to strike the front at the furlong marker before powering clear to win by three and a quarter lengths.
Roger said: "That was a good performance. He is a good actioned horse and he wouldn't want soft ground."