Montreal scored five unanswered goals in the last 22 minutes of the game and swept the home-and-home series after shutting out Boston 1-0 Tuesday.
Trailing 3-1, Plekanec cut the Bruins’ lead with 1:49 left in the second period when he flipped the puck past Bruins goalie Tim Thomas.
Mike Johnson, Maxim Lapierre and Higgins put the game away when they each scored 2:16 apart in the third period to take a 5-3 lead with 11:09 remaining in the game.
Phil Kessel, Marco Sturm and Mark Mowers scored for the Bruins, who lost their third straight.
Jaroslav Halak made 32 saves for Montreal, which scored three power-play goals.
Kessel gave the Bruins a 1-0 lead when he gathered the rebound of his own shot and slid the puck past Halak 2:09 into the game. Kessel’s goal snapped a drought of 143:25 for Boston, which had been shut out the previous two games by the New York Rangers and Canadiens.
Montreal won for the fifth time in the last six games, but won for only the second time in its last eight road games.
After Montreal defenceman Markov tied the game 1-1 at 7:23, Sturm converted a feed from Brandon Bochenski to help Boston regain the lead with 2:27 left in the first.
Mowers made it 3-1 for Boston when he tapped in Kessel’s pass past a helpless Halak 7:32 into the second period.
Ryder scored his 24th goal and Saku Koivu had two assists for Montreal.
Notes: Boston has been shut out three straight games just once in its history – in 1929. … Alex Kovalev has 51 points in 59 games against Boston. … Markov has six goals but two in the last four games. … Boston and Montreal combined for 32 shots on goal in the second period.