Charles de Ketelaere again scored for the impressive victory.
Gasperini said: “There are many reasons to feel satisfied, even if the result was rather amplified in stoppages.
“It was difficult because Genoa are a strong side with enthusiasm and the crowd here gives them an extra boost. Their goal could've completely changed the game, but fortunately Koopmeiners scored and that opened up the spaces for the other goals.
“De Ketelare's first half was extraordinary, even before the goal. This lad has talent and will continue to improve. He has everything it takes to flourish.
“These types of matches can change in an instant, but we did well with the substitutions and to defend well. We are happy for El-Bilal, who had been out of action for almost a year and had two operations, so this can boost his confidence and help him show what he can do."