Greiss was replacing Semyon Varlamov, who had started 14 of New York's 15 games this postseason.
"It was an unreal game, best game I've seen the team play," Greiss said after his first Stanley Cup Playoff Game 7. "They took most of the stuff away. Happy we got the win here."
It was the third game for Greiss this postseason; he made 36 saves in a 3-2 win in Game 4 on Sunday, and made 20 saves in relief in a 4-3 overtime loss in Game 2 on Aug. 26 after Varlamov allowed three goals on 10 shots.
Varlamov was 9-4 with a 2.00 goals-against average and .921 save percentage and two shutouts this postseason. He allowed nine goals in the past two games, each an overtime loss that prevented New York from ending the best-of-7 series.
"The last two games they got to [Varlamov] a little bit in terms of that, and he's played a lot of great hockey for us," New York coach Barry Trotz said. "I wanted the freshness. ... I also knew that with 'Greisser,' just his demeanor, that he'd be a good choice for us."
Varlamov and Greiss alternated the first 33 starts of the regular season before Varlamov started 22 of the final 35.
Greiss was 16-9-4 with a 2.74 GAA and a .913 save percentage in 31 games (29 starts) this season, and Varlamov was 19-14-6 with a 2.62 GAA and a .914 save percentage with two shutouts.
