Viktor Q Went of to many times [Gameplay]

I was playing an ARAM game with Viktor. Near the end of the game when we were taking down the enemies nexus towers, I used the first part of my q on a minion so my empowered basic would act of the tower. When I did this, my empowered basic went off three times on tower. At that point, the tower was destroyed, and didn't occur further amount of times.