PITTSBURGH -- These aren't the Pittsburgh Penguins that the New York Rangers eliminated in the Stanley Cup playoffs the last two years. Not even close.

They're not even the Penguins who began the regular season under a different coach, and that might be the biggest difference of all.

Bryan Rust scored two goals and set up another, fellow rookie Conor Sheary added a goal during Pittsburgh's four-goal second period and the Penguins overwhelmed the New York Rangers with their youth and speed, finishing off the first-round series with a 6-3 rout on Saturday.

"It was great to close it out," Pittsburgh captain Sidney Crosby said.

Goaltender Matt Murray -- yes, he's a rookie, too -- won his third straight game by making 38 saves as the Penguins won their 18th in 21 overall, needing just five games to eliminate the Metropolitan Division rival that put them out of the playoffs the last two seasons.

The difference from then to now is obvious, according to defenseman Kris Letang.

"Before, when Sid (Crosby) and Geno (Evgeni Malkin) didn't score, we had trouble winning games," Letang said. "(Now) we have four lines that can contribute -- and we've got speed."

The Penguins will move on to the Eastern Conference semifinals against the winner of the Philadelphia Flyers-Washington Capitals series. The NHL regular-season champion Capitals lead 3-2 going into Game 6 on Sunday in Philadelphia.

"I think we played a team that's smarter and better," said Rangers goaltender Henrik Lundqvist, who was pulled for the second straight game with New York down 6-2 after two periods.

Every Pittsburgh goal was scored by a player who wasn't on the much-slower Penguins team the Rangers beat in five games last spring.

Rust, whose two-goal game was the first of his career, Sheary and Murray began the season with now-Penguins coach Mike Sullivan at Wilkes-Barre/Scranton (AHL), but they all played pivotal roles in the Penguins' first playoff series win since they beat Columbus in 2014.

Pittsburgh is 37-17-5 since Sullivan moved up from the minors to replace former coach Mike Johnston in mid-December -- and the players he brought with him are becoming difference-makers.

"That's a big part of it, when the coach has trust in you and you know the coach's system," Rust said. "He's done a great job with this team this year, coming in late. It's good for us, coming through."

Phil Kessel, Carl Hagelin and 39-year-old Matt Cullen also found the net as the Penguins shook off two early deficits before steamrolling the Rangers 4-0 during a dominant and decisive second period. Hagelin, a year ago, scored the Game 5 goal for New York York that eliminated Pittsburgh.

The Penguins scored on six of 23 shots against Lundqvist, who frustrated them in the postseason in 2014 and 2015. He gave up 10 goals in the final two games -- Pittsburgh won Game 4 by 5-0 -- or two more than he allowed the Penguins in a five-game series last season.

"The second period, it was a feeling of embarrassment to give up that may goals," Lundqvist said. "It was a sense of hopelessness. ... It was not a good feeling."

Rick Nash, Dominic Moore and Chris Kreider all scored goals on deflected shots for the Rangers, but they hardly made any difference in a series in which New York was outscored 14-4 in the final three games.

"We talked about it before the series, it was going to take everybody in this room -- and simply put, we didn't play well enough," Rangers captain Ryan McDonagh said. "They were a lot better throughout the series. ... It's pretty tough to grasp right now ... it's tough right now sitting in this room."

After Kessel tied it 2-2 on a power play at 11:39 of the first period -- the third goal in a span of 1:39 -- the Pittsburgh kids simply overwhelmed the Rangers and Lundqvist in the second.

"Our team's moving with a lot of speed. (And) we're using our speed to our advantage," Rust said.

Rust, who scored four goals during the season, got it started. Defenseman Trevor Daley faked a slap shot in the high slot only to throw a pass to Rust near the right post for his first career playoff goal at 5:21 of the second period.

Just over four minutes later, Rust pressured Derick Brassard into a turnover and Cullen, who is nearing 40 but isn't at all out of place in the youngish Penguins lineup, picked up the puck in the slot and wristed it by Lundqvist, making it 4-2.

Sheary, moved up to Crosby's No. 1 line earlier in the series, got his second goal of the series at 16:18, and Rust got his second of the period -- and of his playoff career -- at 19:01. Lundqvist finished the period, but Antti Raanta was in net during the third period.

Murray, 12-2-1 during his brief NHL career, made the lead stand up despite allowing Kreider's goal in the third period.

Kessel, Crosby and Cullen all had two-point games and yet another rookie, Tom Kuhnhackl, assisted on Cullen's goal

The Rangers came back from 3-1 playoff deficits against the Penguins in 2014 and the Capitals in 2015, but there were no comeback this time as the Penguins improved to 5-2 all time against the Rangers in the postseason.

NOTES: Rangers D Dan Girardi, benched after being a minus-2 in Game 2, returned to the lineup. D Dan Boyle, a minus-1 in each of the last two games, was benched. Boyle could retire. ... Penguins G Marc-Andre Fleury (concussion) sat out a 10th consecutive game, including the regular season. He skated without pads Friday, but the team hasn't suggested when he might return. Rookie G Matt Murray made a third consecutive start. ... The Rangers had won 15 of their previous 19 elimination games. ... The Penguins are 8-5 all-time in Game 5s when leading a series 3-1. ... Penguins D Brian Dumoulin's assist in Game 4 was the first power-play point of his career, either regular season or playoffs. ... Penguins rookie LW Conor Sheary again started on C Sidney Crosby's top line, with Patric Hornqvist at right wing. ... The Rangers scratched Boyle, D Dylan McIlrath, C Kevin Hayes and RW Marek Hrivik. The Penguins held out D Justin Schultz, RW Beau Bennett, C Oskar Sundqvist and D Derrick Pouliot.