The Penguins are 7-0 in the postseason, still rolling after a four-game sweep of Ottawa in the first round.
They eked out wins at home in the opening two games against the Rangers, rallying from a 3-0 deficit to win Game 1 and prevailing 2-0 on Sunday on the strength of Marc-Andre Fleury's shutout.
Pittsburgh, which lost all four road meetings with the Rangers this season, can advance to the Eastern Conference finals for the first time since 2001 as early as Thursday. Only two teams have come back to win a series after trailing 3-0. The 1975 New York Islanders did it to the Penguins in the second round.
New York, which dominated the shot clock with a 39-17 edge, had the stirring rally in this one, erasing a two-goal deficit in the second period. But Malkin restored the Penguins' lead before the frame was finished, then won a key faceoff in the Rangers end that helped set up Ryan Malone's goal that made it 5-3 at 2:30 of the third.
Marian Hossa, Georges Laraque and Malkin scored for Pittsburgh around a goal by New York's Martin Straka in the first period.
Ryan Callahan and Jaromir Jagr struck 1:04 apart in the second to tie it.
The Rangers held a 15-9 shots edge in the first period and 14-4 through 40 minutes, but trailed for most of the game.
Just when it seemed the Rangers were going to blow right past the Penguins, a careless boarding penalty by Ryan Hollweg put Pittsburgh back on the power play. And despite being outshot 29-13, the Penguins regained the lead with another advantage goal.
New York pressed for the go-ahead score after its two quick ones forged a 3-3 tie. The Penguins were tired in their own zone when Hollweg, a healthy scratch for the first two games of the series, drilled Petr Sykora from behind into the boards.
With quick, crisp passes that slid all over the Rangers end during the advantage, the Penguins moved the New York defenders around in exhausting fashion. Callahan struggled to keep up, even crouching to go into shot-blocking position, despite being out of gas. Sidney Crosby's pass nicked Callahan before getting to Malkin in the right circle.
Malkin took his time and sent a shot into the net off the left post to make it 4-3 with 2:07 left in the second. Last season's rookie of the year has five goals in the playoffs, three in this series.
It took all of the exhilaration out of the Madison Square Garden crowd that went from listless, after a discouraging first period, to jubilant when Jagr's sweeping move from behind the net finished with a deft shot into the top left corner of the net.
Pittsburgh took control in the first after shaking off the Rangers' first tying goal of the night and pushed their lead to 3-1 on goals by Laraque and Malkin 1:24 apart.
Laraque, who scored only four times in the regular season, snapped off a shot from in front after a pass by Malkin from behind the net at 16:17. Just 52 seconds after 5-foot-11 Callahan took a 4-minute high-sticking penalty for clipping 6-7 defenseman Hal Gill, Malkin netted his first of the night.
Except for the closing seconds of Game 2 when Adam Hall sealed Pittsburgh's win with an empty-netter, this marked the first time the Rangers trailed by more than one goal this postseason.
As has been the case in all three games, the power play has made the difference on both sides. Pittsburgh has scored at least one man-advantage goal in each of its seven postseason games, including four in this series.
The Rangers were 0-for-5 on the power play in this one and are 1-for-14. New York was given three straight advantages within a 2:08 span early in the second period, but couldn't convert. The overlap gave them two 5-on-3 power plays that totaled 75 futile seconds.
Hossa staked the Penguins to a 1-0 lead 1:02 into the game with his third of the playoffs. The Rangers tied it with 5:28 left in the first on Straka's goal that came when Jagr crashed the net.
After a video review and a heavy scrum that produced six roughing penalties, the goal was credited with Jagr, Brandon Dubinsky and defenseman Paul Mara pounding the glass in celebration from inside the penalty box.
The goal was allowed to stand because the net popped off its moorings after the puck crossed the line.
