PITTSBURGH -- Generously listed at 5-foot-8 and 192 pounds on the Pittsburgh Penguins' website, it is easy to question the size of left winger Conor Sheary.

What isn't in dispute is the significance of his robust production as of late. Collecting two goals for the third time in four games, Sheary sparked the Penguins to a 5-1 win against the fading Boston Bruins on Sunday at PPG Paints Arena.

The Penguins have won four consecutive games while the Bruins have lost four straight.

"It's going better than I expected at this point," said Sheary, who also recorded an assist. "I think it's a mixture of a lot of things, the way we're playing as a team and the way our line is playing, I think it's just been clicking now. These streaks usually don't last. I'm just going to enjoy it while it's here."

After a scoreless first period, the Penguins took the contest's first lead 18 seconds into the second.

Taking a backhanded pass off the boards from Sheary, center Sidney Crosby raced through the neutral zone and gained the offensive zone with speed. Creating a two-on-one with right winger Bryan Rust against Bruins defenseman Zdeno Chara, Crosby fed a forehand pass to Rust, who beat goaltender Tuukka Rask's glove hand with a forehand shot.

That trio combined again to give the Penguins a 2-0 lead at 9:06 of the second. After Rask stopped a deflected shot, Crosby kept the rebound free and allowed Rust to whip a wrister on net from the left circle. Rask stopped that shot, but allowed a rebound to bounce loose to the right of the cage where Sheary chopped home.

Rask left the game at 11:48 of the second due to a migraine headache which limited his vision and was replaced by Zane McIntyre.

"Seeing lights a little bit and then it got bad really quickly. It lasted a half hour. Got my vision back when a couple of minutes was played in the third period."

The Bruins got on the scoreboard at 13:49 of the second. From the high slot, Bruins right winger David Pastrnak fed a forehand pass to center David Krejci above the right circle. Moving into the circle, Krejci pounded a slapper past the blocker of goaltender Matt Murray on the far side.

The Penguins regained a two-goal lead at 18:20 of the third period. Corralling a puck at the right point, Chad Ruhwedel whipped a wrister toward the net. After the puck glanced off the stick of Bruins defenseman Brandon Carlo, Penguins right winger Patric Hornqvist was able to control the rebound above the crease and tucked a backhander past McIntyre's right skate.

Sheary's second goal of the contest gave the Penguins' a 4-1 lead at the 17:01 mark. After having a shot blocked in the slot, Penguins defenseman Justin Schultz recovered his own rebound and fed a pass to the right of the crease where Sheary, an undrafted player in the midst of his second NHL season, snapped his 17th goal of the season past McIntyre's glove hand.

"I felt strongly that Conor could be a good player in this league," said Penguins head coach Mike Sullivan. "He's real elusive, he has great quickness to his game, he has a high hockey I.Q. and he's brave. I'm not going to suggest I thought he'd have 17 goals halfway through the season, but I knew he could play in this league and he could be a solid player at the NHL level."

The Penguins' fifth goal came on a power play at the 15:23 mark. Right winger Phil Kessel fed a pass from the left-wing wall to Crosby alone above the crease. Going forehand to backhand, Crosby was able to tap the puck past the glove hand of a sprawling McIntyre.

Murray improved to 17-4-1 after making 44 saves. Rask fell to 22-12-4, making 20 saves before leaving the game.

Bruins coach Claude Julien was questioned if his entire lineup offered enough of a contribution.

"It's frustrating," Julien said. "There's a lot of guys right now that aren't giving us enough and this is a team that I think needs all 20 guys going in order to win. We don't have enough talent to think we can get away with a mediocre game.

"I want guys that care, I want guys that want to come in and give it all every night. We need more of that and we don't have enough right now."

The final 6:26 of the first period was delayed due to damage to the ice. During a television stoppage, arena employees attempted to repair a patch along the boards near the Penguins' bench, but took so long that officials sent each team to its respective dressing room and began the first intermission early. The remainder of the first was played prior to the start of the second.

NOTES: Penguins head coach Mike Sullivan suggested D Brian Dumoulin could return to the lineup before the All-Star Break, which begins Friday. Dumoulin has missed 10 games due to a broken jaw. ... The Penguins scratched C Matt Cullen (foot), RW Tom Kuhnhackl (healthy) and D Steve Olesky (healthy). ... With the Steelers and Patriots facing off in the AFC Championship Game later in the evening, Penguins C Evgeni Malkin arrived at PPG Paints Arena wearing the jersey of former Steelers S Troy Polamalu. ... The Bruins scratched D Kevan Miller (concussion) and RW Jimmy Hayes (healthy). ... G Tuukka Rask started his seventh consecutive game. ... Saturday, the Bruins assigned LW Anton Blindh to Providence of the American Hockey League.