The Lightning lost two players during the game -- Bishop and forward Valtteri Filppula.
Bishop was hit in the head by the knee of teammate Nikita Kucherov and had to leave the game.
While Bishop was sprawled on the ice, Methot gave Ottawa a 1-0 lead. Erik Karlsson also scored for the Senators in the first period, Ottawa came up with second-period goals from Zack Smith and Kyle Turris and Bobby Ryan scored in the third period to give the Senators a 5-1 lead.
Filppula left in the opening period with a lower body injury and did not return.
Craig Anderson made 35 saves to collect the victory. Anders Lindback replaced Bishop and stopped 23-of-27 shots.