The 20-year-old forward got City going with an opening goal in the eighth minute before he hustled to win the ball and help Fernandinho double the advantage in the 11th.
Sevilla's Benoit Tremoulinas scored for the hosts in the 25th, only for former Sevilla fan favorite Jesus Navas to pass for Wilfried Bony to take City's third in the 36th.
City moved into first place in Group D with nine points with two games left. Sevilla has three.
In the other group game, Juventus drew 1-1 at Borussia Moenchengladbach to fall into second with eight. Moenchengladbach is last with two.