The Bruins look to extend their longest winning streak in three months and clinch a playoff berth Thursday night when they host a Capitals team coming off a discouraging loss.
Boston (45-28-3) was a point out of first place in the Northeast Division on March 16 but has since gone 5-1-0 to open a five-point lead over Ottawa with a game in hand. It is also four points ahead of Southeast-leading Florida for second place in the Eastern Conference.
The Bruins have a nine-point advantage over ninth-place Washington and can secure a playoff berth with a victory.
"We're putting together some points at a very important time," goaltender Tim Thomas said after Tuesday's 5-2 win over Tampa Bay.
The Capitals (38-31-8) have been squandering opportunities to gain points in the last two weeks, and Tuesday's 5-1 loss to Buffalo could end up costing them a shot at the playoffs.
Washington entered the game tied with the Sabres with 84 points but was in possession of eighth place. The Capitals are now two points back of Buffalo and four behind the seventh-place Senators, with all three teams having five games left.
"Now we're going to start needing a little bit of help," forward Mike Knuble said. "You've got to set a target of trying to get four out of these five and finish extremely strong. And then even if you do that and hold up that end of the bargain, you've got to wait for a little bit of help somewhere else."
It is a troubling position for the Capitals, who had a four-point cushion for the final playoff spot before going 2-3-2 in their past seven contests.
"We got to do whatever it takes to win hockey games right now," center Matt Hendricks said. "We know what's on the line, we know where we sit in the standings and it's going to be a desperate hockey team."
To earn a fifth straight playoff berth, Washington needs to get consistent play on both ends of the ice.
Against Buffalo, the Capitals had 45 shots but only Alexander Semin scored. Alex Ovechkin's five-game point streak came to an end, and he misplayed a puck on the power play directly leading to Buffalo's fourth goal late in the second period.
Braden Holtby was already gone by that time, as he was pulled 2:31 into the second after yielding three goals on 18 shots. He had stopped 55 of 56 shots in his previous two games.
While Washington is limping down the stretch, the Bruins are putting together some impressive performances.
Boston, on its first three-game winning streak since a seven-game run Dec. 10-28, has outscored opponents 24-10 in its last six contests following a four-game losing streak. A 4-3 home defeat to the Capitals on March 10 started that skid.
Thomas is 4-1-0 with a 1.58 goals-against average and a shutout in his last five games after going 0-3-0 with a 5.73 GAA in his previous four.
Benoit Pouliot has led the charge offensively in the last six games with four goals and four assists, while Zdeno Chara has three goals and three assists and Brad Marchand has three goals and two assists.
Marchand has scored in each of the three games against Washington this season, but the Bruins have lost twice.
"We just want to play really well going into the playoffs," Chara said. "This time of the year you have to get your game established and play the right way."
AccuScore has powered more than 10,000 simulations for every NHL game on ESPN.com, calculating how each team's performance changes in response to game conditions and opponent's abilities. Each game is simulated and the game is replayed a minimum of 10,000 times to generate forecasted winning percentages.