The Devils head on the road Wednesday to play the Boston Bruins. Puck drop is 7:08 p.m. EST.
Leo Komarov tied the game up at 14:25 of the first frame. But every time the Islanders made moves, the Devils responded.
Nikita Gusev scored his second goal of the pre-season at 8:31 of the second to put New Jersey on top 2-1. He roofed a backhand past the goaltender on a rush down the ice. Hischier recorded his second assist of the night on the goal.
Mathew Barzal got the Islanders back to even at 10:19 of the middle frame, but - again - the Devils responded.
Will Butcher was the goal-scorer this time for New Jersey, rifling a shot through from the top of the circle at 16:50 of the second. Hischier notched his third assist of the game on that goal and Gusev also had a helper.
The Islanders would get yet another equalizer, this time from Otto Koivula at 5:59 of the third period, which made it a 3-3 game headed down the home stretch.
Just as he started the scoring, Boqvist finished it with a power-play goal. He potted the eventual game-winner at 15:57 of the final period of play.