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The Washington Capitals put the defending Stanley Cup champion Boston Bruins on the brink of playoff elimination with a 4-3 win in Boston on Saturday to grab a 3-2 series lead in the Eastern Conference quarter-final.

The seventh-seeded Capitals, who only earned a playoff berth in their penultimate game of the regular season, can close out the best-of-seven first-round series with a win over the second-seeded Bruins in Washington on Sunday.

With 87 seconds to play in regulation, Washington's Troy Brouwer scored the winning goal on a power play when he sent a shot over the shoulder of Boston goalie Tim Thomas.

Washington grabbed a 3-2 lead early in the third period when Mike Knuble sent a big rebound past a sprawling Thomas, but a Johnny Boychuk slapshot from 60-feet tied the game five minutes later with 11 minutes to play.

Washington had a 2-0 lead just past the midway mark of the second period on goals from Alexander Semin and Jay Beagle.

But the Bruins responded three minutes later when Dennis Seidenberg and Brad Marchand scored 28 seconds apart, sending the home crowd at TD Garden into a frenzy leading into the second intermission.

(Reporting by Frank Pingue in Toronto; Editing by Larry Fine)