NEW YORK -- For years, the Pittsburgh Penguins have been vexed by a lack of depth in the postseason. Their stars were always reliable but they rarely received contributions from anyone outside that core as they failed to go deep in the playoffs.

In Game 3 of their first-round series against the New York Rangers on Tuesday night, the heroes were a 39-year-old bottom-six forward and backup goaltender.

Center Matt Cullen scored a tie-breaking goal early in the third period and goaltender Matt Murray won his postseason debut as the Penguins smothered the Rangers in a 3-1 victory that gave them a 2-1 lead in the best-of-seven series.

"He's a player, eh?" Penguins right winger Phil Kessel said of Cullen. "You watch him out there and he can play for a lot more years. He skates well. He's smart. You can put him in every situation. He's just a great player."

Cullen's game-winning goal was mostly an individual effort. He chipped a loose puck between Rangers defensemen Dan Boyle and Keith Yandle and took off on a breakaway. Staring down Henrik Lundqvist, Cullen snapped a shot through the goaltender's legs for his second playoff goal in 14 games across six years.

"He gets clutch goals," said Sidney Crosby, whose power-play goal with 42 seconds remaining in the second period tied the score at 1. "It's a really close game, he gets sprung there and makes a great play. It's going to take everybody in order to keep winning games here but it was a big play from him to get us that lead."

Murray, who made 16 saves, didn't have to do much to preserve it; the Rangers mustered just four shots on net in the final period and were unable to generate anything in the final minute with Lundqvist on the bench for an extra skater. Defenseman Kris Letang added an insurance goal with 11.2 seconds remaining to ensure the Penguins' victory.

The 21-year-old took the reins from goaltender Jeff Zatkoff, who played the first two games of the series while Marc-Andre Fleury was out with a concussion. Murray suffered his own head injury in the regular-season finale and did not dress for the first two games of this series but had almost no rust in Game 3.

The fact he only had to face 17 shots made his life that much easier.

"I mean, 17 shots on net kind of speaks for itself," Murray said. "We were pretty dominant. We had the puck most of the time. When we didn't, we defended really well. That definitely makes my job a lot easier."

The Penguins fell behind 39 seconds into second period when left winger Rick Nash beat Murray on a shorthanded breakaway that put the Rangers ahead 1-0. But Kessel was able to set up Crosby for the tying goal late in the period after former Ranger left winger Carl Hagelin drew a penalty.

"You hate giving up a goal in the last minute of any period," Rangers center Derek Stepan said. "As a group, I think we had the right idea, the right intention and we felt good about our first two periods but as a group I think we have to get through that neutral zone."

"Our biggest issue was we couldn't make any plays with the puck," Rangers coach Alain Vigneault said. "Whether it be breaking out of our end, going through the neutral zone or once we got in their end, we just didn't make enough plays. We have to give them credit -- that was a real solid defensive performance."

From top to the bottom, it was the Penguins' best showing of the postseason. If they can replicate it moving forward, Game 4 may be the final game at MSG this season.

"You see it in the playoffs -- the role players score a goal," Cullen said. "It's important for our line to generate offense, whether we score or not. You know these are going to be some close games. They are all tight. Any opportunity you can create and get pucks on the net, the better."

NOTES: Penguins G Marc-Andre Fleury missed his third straight game in the series with a concussion. He did not skate in the morning and is still listed as day to day. ... Among the Penguins scratches were D Justin Schultz, D Derrick Pouliot and RW Beau Bennett. ... With D Ryan McDonagh back from a hand injury, the Rangers scratched D Dylan McIlrath. ... Rangers D Dan Girardi missed his second straight game with what the team called a general body injury. ... Rangers D Raphael Diaz was a healthy scratch.