PITTSBURGH -- The Boston Bruins took advantage of the absence of Kris Letang in terms of shots on goal, attack-zone time and chances.
Where they couldn't take advantage was with goals.
Even without their top defenseman, the Pittsburgh Penguins aren't allowing many of those these days.
Sidney Crosby and Joe Vitale scored, Tomas Vokoun made 31 saves and the Penguins extended their winning streak to nine with a 2-1 win Sunday afternoon against the Bruins.
Pittsburgh has allowed a total of five goals over its past five games.
"Our team defense has been a focus for us and how we play -- and it's everybody," Penguins coach Dan Bylsma said. "The responsibilities of our fowards in the defensive zone has been a key for us both offensively and defensively."
Pittsburgh (22-9-0) took over sole possession of first place in the Eastern Conference with the win, its seventh consecutive at home. The Penguins built a 2-1 lead during the first 19:28 and protected it through the final two periods despite not having Letang available in that time.
The NHL's scoring leader among defensemen, Letang sustained a lower-body injury. The team did not elaborate on the nature of the injury or when it was sustained, but television replays showed Letang gesturing in apparent pain after taking a slash from Boston's Brad Marchand. Marchand's skate also perhaps made contact with the back of Letang's leg on the play.
After the game, Letang was seen in street clothes but not in any sort of boot or cast. The only update the team gave was that he would be further evaluated, Bylsma said.
Pittsburgh already was without the services of reigning League MVP and scoring champion Evgeni Malkin, who missed his fifth straight game because of an upper-body injury.
"That's two guys that log a lot of minutes and we depend on pretty heavily," Crosby said. "But guys always look at that as maybe an opportunity to step up and fill a different role. That's the way we have to look at it; it's not something we want to deal with but if that's the case we have to keep finding ways to keep rolling and keep playing well."
The Penguins beat the Bruins for the fifth time in a row and second time at Consol Energy Center in the past six days. This game was for sole possession of first place in the conference standings.
Tyler Seguin scored for Boston, which has lost two of its past seven -- both to the Penguins. Playing their fifth game in seven days, the Bruins had a 32-18 edge in shots Sunday.
"I'm not disappointed in our effort today," Boston coach Claude Julien said. "Our third game in four nights, I thought we competed hard, thought we had a chance to win. We spent more time in their end, and we did all the things right -- except we couldn't get that goal."
The Bruins also had a prominent player leave the game because of injury. David Krejci was struck square in the right knee by a slap shot while he leaped in front of the net. He was down on the ice for several moments and needed to be helped to the bench, not applying any weight onto the leg.
The only official update on Krejci's condition the team provided after the game was Julien saying that it is not been ruled out that he will accompany the team on its trip to Winnipeg in advance of a game against the Jets on Tuesday.
Krejci, who is second on the team in points with 24 in 27 games, was seen walking under his own power after the game.
The Penguins scored the game's first goal for the 21st time this season, tied with the Montreal Canadiens for most in the NHL.
Seconds after being stopped by Tuukka Rask following splitting two Boston defensemen, Crosby made it 1-0 with his 13th of the season 12:06 into the game. The NHL's scoring leader received a pass from Chris Kunitz while in the slot, slowly skating backward to the right wing. Crosby hesitated momentarily before releasing a rising wrist shot that Rask was too late in lunging over to stop.
Seguin tied it 4:32 later when a Johnny Boychuk shot from the right point deflected off a skate in the slot and came right to a wide-open Seguin, who was to the right of Vokoun.
The goal was Seguin's 10th of the season, seventh in his past 10 games and 50th in 182 career contests.
"Sometimes when you get up by a goal or two you can sit back, and that might have been what happened with Pittsburgh there," Marchand said. "And it kind of lit a fire under us. We knew we were battling to come back and sometimes you dig a little deeper. But we couldn't come through."
Vitale scored what was ultimately the winner during the final minute of the first period. Rask could not handle a Craig Adams shot from the point cleanly with his glove, leaving a rebound for a wide open Vitale to flip into the roof of the net for his first of the season.
"You don't see many of those [rebounds] in the game -- especially, I don't see many of those in the game," Vitale said. "So it was nice.
"Obviously, scoring isn't something I pride myself on every night or else I don't think I'd have a job up here... To chip in and help the guys out in a one-goal game like this, a big game against Boston, is pretty exciting."
Vitale's most recent goal was Feb. 26, 2012 against Columbus. The tally also was only the second of the season -- not counting empty-net goals -- for the Penguins' usual fourth line of Vitale, Adams and Tanner Glass.
"Seeing [Vitale] get a big one for us before the end of the first period and [Vokoun] playing big tonight, it seems like it's always different guys stepping up," Crosby said. "That's what you need in order to have success consistently, and we've been getting that lately. Our depth is a big part of our success. We need to continue to show that."
That depth could be tested further moving forward if Malkin and Letang remain unavailable.