With a three-games-to-none lead in their Eastern Conference quarterfinal series and a two-goal advantage early in the first period of Game 4, the New York Islanders appeared primed to advance to the second round of the playoffs Tuesday night.

But nobody has to tell New York coach Barry Trotz how hard it is to finish off a team with a championship pedigree like the one possessed by the Washington Capitals.

The Islanders will once again try to eliminate the Capitals on Thursday, when the two teams face off in Game 5 in Toronto.

The Islanders scored twice in the first 10 minutes of the first period in Game 4 before the Capitals scored the game’s final three goals — the last two by captain Alex Ovechkin — to stave off elimination with a 3-2 win.

Mathew Barzal’s goal at 9:16 of the first put the Islanders ahead 2-0. But the Capitals regained