Markov took advantage of a power play that came when Matt Lashoff, the Bruins' first overall pick in the 2005 draft who was making his NHL debut, was called for holding with 45 seconds left. The Canadiens defenceman got the puck to the left of Tim Thomas and put it between his legs for the game-winner.
While Montreal players - and some of their vocal fans in the Boston crowd - celebrated, others in the stands began throwing cups and other trash onto the ice. After about a minute, and a futile announcement from the public address announcer, the clock started and the buzzer blew while both teams were still at their benches and the ice crew was cleaning up.
Cristobal Huet stopped 34 shots for Montreal, which has won eight of nine against its longtime rival, including the last six in a row. Michael Ryder and Chris Higgins also scored for the Canadiens.
Thomas made 26 saves for Boston, making a sprawling save on Mike Johnson with 3:25 left to temporarily preserve the tie. He fell to 1-6 against Montreal in his career.
Zdeno Chara scored his first goal since joining the Bruins in the off-season as one of the top prizes on the free agent market. Phil Kessel scored and Glen Murray and Patrice Bergeron had two assists apiece for Boston.
The Canadiens lost forward Alex Kovalev in the second period when he whacked his stick across the glass after drawing a penalty for jostling with Boston defenceman Milan Jurcina. Kovalev was given two minutes for unsportsmanlike conduct and a game misconduct.
While he was out, Craig Rivet picked up a double minor for hooking and slamming his stick. The Bruins used the two-man advantage to tie it up on Chara's slapshot with 91 seconds left in the second.
Notes: Bruins forward Marco Sturm missed his third consecutive game with a leg injury. ... P.J. Axelsson left the ice in pain after getting slashed on the left hand with six minutes left in the game. ... The Canadiens wore white sweaters with a blue stripe. ... Former Bruins first-round draft choice Sergei Samsonov returned to Boston for the first time since he was traded to Edmonton in March.