But Federer remained serene throughout and, like a true champion, raised his level when it counted, breaking with a backhandpass in game 12 to take the vital set.
During one sequence, Nash fed Ryan Callahan, who spun around as he drove to the left post and sent a perfect no-look backhandpass across the crease to a hard-charging Derek Stepan.
But Tavares, the No. 1 overall draft choice in 2009, gave the Islanders a 1-0 lead just 5:36 into the game by taking a backhandpass from Josh Bailey, taking an extra beat to pick a spot, then snapping a shot over the glove of Penguins goaltender Tomas Vokoun.