Rask stopped 23 shots and the Bruins received goals from Miroslav Satan and Dennis Wideman in a 2-1 win over the Rangers on Sunday afternoon at TD Garden.
Boston moved five points ahead of 10th-place New York in the standings, while increasing its lead over ninth-place Atlanta to three points, pending the outcome of the Thrashers' game in Philadelphia later Sunday.
"I can't even remember when we won the last game 2-1," Rask said, "but it's something the team needs. We need these tight games and we need to win them. I think that's going to help us."
"Sure, this was a team that we're chasing and we needed those points," forward Vinny Prospal said. "It's a big loss for us, but, on the other hand, we can't just say it's over."
With both teams coming out realizing the importance of this game, the goal light operator had a quiet first period but the officials had plenty of work to do. They assessed 28 minutes in penalties to the two sides, including fighting majors to Brandon Prust of the Rangers and Steve Begin of the Bruins at the 2:40 mark.
The Rangers also had a very brief 5-on-3 advantage after minors to Mark Recchi and Dennis Wideman, but didn't manage a shot against Rask in the 11 seconds before Recchi was released from the penalty box.
Bruins captain Zdeno Chara, who picked up a pair of roughing calls in the first, put his team at a four-minute disadvantage after a high-sticking rap 8:30 into the second. But the Rangers came up empty again, without even a shot on goal.
"It was a key point in the game," New York captain Chris Drury said. "It kind of livened them up a little bit."
The action heated up shortly after that. Sean Avery hit the post for the Rangers with about four minutes left and on the ensuing Bruins rush, Daniel Paille was dragged down on a breakaway and awarded a penalty shot. Henrik Lundqvist stopped him with 3:47 remaining in the period to keep the game scoreless, but Satan struck moments later.
Defenseman Andrew Ference took a Johnny Boychuk pass at the blue line and carried the puck down the left wing boards, drawing several defenders to him. From the left circle, he threaded a perfect cross-ice pass to Satan, who had the open right side of the net in which to deposit the puck. Satan's fifth of the season came with 3:24 left in the second.
"He comes up with a big save there and then the next shift they score a goal where we have three guys staring at the puck," Rangers coach John Tortorella said. "It's a tough one."
Wideman put the dagger in with 9:40 remaining in the third, stopping a Vladimir Sobotka pass with his skate and then whipping a backhander past Lundqvist from the left circle.
"We were skating a lot more. We were battling," Wideman said. "We were a lot more prepared to play than we were on Thursday (a 3-0 home loss to Pittsburgh)."
Lundqvist kept the Rangers close by making a great stop against Michael Ryder off a 3-on-1 break with eight minutes left, but was done in once again by a lack of offensive support from his teammates. Del Zotto ended Rask's shutout bid on a drive from the blue line with 3:04 remaining, but New York couldn't manage the tying score after pulling Lundqvist for the game's final minute.
"It's been an effort the past few weeks to try to stay positive," Lundqvist said.
The Rangers also lost forward Ryan Callahan, who left the game with a lower-body injury after a collision with Chara late in the second and did not return.
Material from wire services was used in this report.
1 - 0 BOS
2 - 0 BOS
Michael Del Zotto
2 - 1 BOS
Hi stick - double minor