Bruins 5, Capitals 4

-- The buzzer at the end of the third period today did not signal the end of the game -- overtime remained to be played -- but for the Washington Capitals it was a welcome sound. The Capitals fought back from a 3-0 deficit to tie the score at 4 through regulation time, securing at least one standings point.

When Boston's Sean O'Donnell officially ended the affair with his goal midway through overtime, giving the Bruins a 5-4 win at FleetCenter, the Capitals were not completely disappointed. They had put forth one of their gutsiest efforts of the season, extending their points streak to seven games and Southeast Division lead to two points over Tampa Bay.

"It's always a little bit disheartening to lose," said winger Mike Grier, who scored a crucial shorthanded goal. "But to be down 3-0 to a pretty good hockey club in the first period and to work our way back and play as a team and never give up is definitely a big positive for us."

The Capitals rallied around rookie backup goalie Sebastien Charpentier, who replaced starter Olaf Kolzig 10 minutes in with a three-goal deficit, and relied on their core of veterans to crawl back into the game. Coach Bruce Cassidy had perhaps the best tactical game of his rookie season, tweaking his lineup midway through the contest and making alert changes on the fly against the Bruins, who are fighting for the last playoff spot in the Eastern Conference.

"That atmosphere and all the line matching, that was as close to a playoff game as we had all year," team captain Steve Konowalchuk said.

Cassidy redistributed grit through the lineup and worked hard to get Jaromir Jagr favorable matchups by double-shifting him with different lines. Cassidy also benched defenseman Jason Doig in the third period, riding five defensemen down the stretch.

"I don't like the way [Doig] has played lately, and he was fighting the puck and his feet weren't moving," Cassidy said, perhaps underlining the need to add a veteran defender before Tuesday's trade deadline.

Washington's troubles were all-encompassing in the first period. Cassidy opted to give his rarely used fourth line -- known more for its toughness than playing ability -- its first shift at the same time he used his inexperienced third defensive pair, Doig and Joel Kwiatkowski. Doig upended Kolzig, allowing P.J. Axelsson to score easily about six minutes in.

The Bruins' power play, which has scorched the Capitals this season (7 for 19), took over from there. Glen Murray scored successive goals -- one on a slap shot from the point and another from long range when Kwiatkowski screened Kolzig, and the goalie was yanked for the first time this season after allowing three goals on six shots.

"My split-second decision was: Let's get [Charpentier] in there," Cassidy said. "Maybe the guys will rally around him. They know he hasn't played much, they know how hard he works in practice. He's a good kid, they want to play hard for him and it showed."

Charpentier went on to stop 26 of the 28 shots he faced -- "You try not to put pressure on yourself in that situation," the 25-year-old said, "but it's 3-0 and I'm going in cold and the guys played extremely hard when I went in." -- and immediately after the backup entered the game, enforcers Alex Henry and Stephen Peat and defenseman Brendan Witt all dropped the gloves, sending a message that the team would not roll over.

"It's a tough job to go out there and fight and get the momentum back for us," Grier said. "But they did and it was big."

Konowalchuk notched his 14th goal of the season, and first on the power play, three minutes later and Grier, who grew up in Boston, cut the deficit to 3-2 with a brilliant individual effort while his team was short-handed. Grier stripped Joe Thornton of the puck with a beautifully timed poke check and converted his breakaway by lofting a backhander past goalie Jeff Hackett's stick less than five minutes into the second period for his first goal in 12 games.

The Capitals responded 90 seconds later on the power play, which entered the game in a 3-for-52 slump but went 2 for 3 today. Robert Lang, who had not scored in eight games, took a routine wrist shot that Hackett muffed and Peter Bondra capped the comeback 93 seconds into the third period, taking a pass from Michael Nylander with not a Bruin in sight and redirecting the puck into the near side, undoubtedly the more resonant of the 25 goals he has scored this season.

Capitals Notes: Top prospect Nolan Yonkman, who has played only 23 games for the Portland Pirates because of injuries, will undergo surgery on the orbital bone around his left eye next week, and will miss six weeks, which puts him out until at least late in the first round of the playoffs. . . .

General Manager George McPhee and his scouts and assistants will sequester themselves in the team's offices beginning Sunday as preparations for the trade deadline begin in earnest. The club has no deals in the works, sources said, but is exploring options for an experienced defenseman and veteran winger to round out the fourth line. . . .

Winger Kip Miller (hand) and defenseman Jean-Francois Fortin (back spasms) did not play, although Miller is expected to return shortly. Defenseman Rick Berry and forward Josh Green were healthy scratches.

Michal Grosek checks Capitals' Brendan Witt into Bruins' bench. Caps earned a point in seventh straight game, after scoring on two of three power plays.