The Capitals' Alex Ovechkin scored a pair of goals for his league-leading 42nd and 43rd of the season. With his two-point performance, he also reached 800 career points. Teammates Joel Ward and Eric Fehr also scored for the Capitals, while goaltender Braden Holtby finished with 36 saves.
Penalties and turnovers hampered Boston's chance, and the Capitals took advantage of those miscues. The Bruins had a golden opportunity early in the first period with a two-minute 5-on-3, but Washington killed off Boston's two-man advantage.
Washington gained a 1-0 lead on Ovechkin's power-play goal at 18:39 of the first period. With the Bruins' Chris Kelly in the penalty box for interference, the Capitals gained control and set up a one-timer for Ovechkin from the left faceoff circle.
Ovechkin gave the Capitals a 2-0 lead with his second power-play goal of the game at 2:24 of the second period. Rask had no chance on Ovechkin's one-time blast from the left faceoff circle.
The Capitals gained a 3-0 lead at 10:13 of the second period. After a center-ice faceoff, Bruins defenseman Johnny Boychuk turned the puck over and Ward gained control, broke in and beat Rask with a backhander.
Despite the three-goal deficit, the Bruins finally woke up and began to chip away at Washington's lead.
The Bruins scored on the power play when Dougie Hamilton made a nice slot feed to Bergeron, who notched his 17th goal of the season, going top shelf on Holtby at 10:54 of the second period. Boston cut its deficit to one goal when Thornton notched his fifth of the season at 17:32 of the second. The Bruins' fourth line was buzzing and Thornton made a centering pass to Campbell, who was crashing the net and appeared to redirect the puck past Holtby. But Thornton was given credit for the goal, and Boston trailed 3-2.
Washington capitalized on another Bruins turnover in the offensive zone when Fehr collected the loose puck at the defensive blue line and broke in all alone on Rask and beat him to the 5-hole to give the Capitals a 4-2 lead at 10:53 of the third period.
Save of the game: With the Bruins trailing 3-2 early in the third period, the Capitals gained control in the offensive zone when Washington's Troy Brouwer created a point-blank scoring opportunity and attempted to go high glove on Rask, but Boston's netminder snared the puck with precision to keep the Bruins within striking distance.
Looking back: It was 17 years ago today when the Bruins traded Adam Oates, along with Bill Ranford and Rick Tocchet, to the Capitals in exchange for Jim Carey, Anson Carter, Jason Allison and a third-round pick (Lee Goren). Oates, a Hall of Famer and current Capitals coach, talked prior to Saturday's game and didn't realize it was the anniversary of the trade. He was speaking in general terms of the upcoming trade deadline when he was asked about his trade.
"Different plot was the reason," Oates said. "The Bruins were struggling, and it turned into a big deal. I came out publicly, so it was a different scenario. It was a couple of weeks, but you knew it was coming."
During the 1996-97 season, the Bruins spent the season in the basement of the Northeast Division. After a February game in Colorado, Oates went off on the Bruins' organization. It was only a couple of weeks later when the Bruins traded Oates to Washington.
Up next: March is a busy month for the NHL with a condensed schedule due to the recent two-week hiatus for the Winter Olympics. The Bruins have 17 games in March and six pairs of back-to-back games, starting Sunday. After Saturday's loss to the Capitals, the Bruins travel to New York to face the Rangers on Sunday night at Madison Square Garden.