The goal gave Malkin 172 career playoff points (64 goals, 108 assists), tied with Mario Lemieux for second in Penguins history and 19 behind Crosby.
Anthony Beauvillier tied it 1-1 at 19:05 of the first. After skating around Jake Guentzel, Beauvillier drove to the net for a wrist shot over Jarry's blocker.
"You want to get on the board, obviously," Beauvillier said. "A big goal for us to tie it up at 1-1 before the end of the period. It was big for us."
Bryan Rust put the Penguins ahead 2-1 with a one-timer set up by Crosby at 7:37 of the second period. The assist moved Crosby past Brett Hull into sole possession of seventh all-time in playoff points with 191 (69 goals, 122 assists).
"I think we're going to work together," Rust said. "I think we're going to lift our heads up and try to win. Obviously, this is a race to four. Our backs are against the wall now, and we just have to work hard to get the next two."
NOTES: Sorokin became the first Islanders goalie to win his first three playoff games. He made 39 saves in a 4-3 overtime win in Game 1 and 29 saves in a 4-1 win in Game 4. Semyon Varlamov started when New York lost Games 2 and 3. ... Letang had 10 hits in 37:20 of ice time during his 141st playoff game, passing Jaromir Jagr for sole possession of the third most postseason games played in Penguins history. Crosby is first with 173 and Malkin is second with 169. … Islanders forward Oliver Wahlstrom is day to day after leaving the game with 8:03 remaining in the third, when he was hit into the boards by Penguins defenseman Mike Matheson, Trotz said.