The hosts began brightly, with Artem Fidler flashing a low ball across the face of goal inside the opening two minutes.
Cisse almost gave Kuban the lead a minute before the break, but he could only direct his header narrowly wide of the post.
Five minutes after the restart, Piatti stung the palms of Benelov after cutting in from the left and unleashing a powerful drive at goal.
Piatti was involved again soon after when he picked out Federico Cartabia in the box, but the Argentine's effort was easily gathered by the goalkeeper.
Valencia were gifted their opening goal on 73 minutes by Benelov when the Russian stopper rushed out of his goal in an attempt to intercept a long ball. However he missed the ball, allowing Alcacer the opportunity to tap into an empty net.
Feghouli made it 2-0 with nine minutes remaining when he curled a free kick past Benelov from the edge of the area after Cartabia had been fouled.