BOSTON -- Defenseman P.K. Subban's power-play goal 4:17 into the second overtime lifted the Montreal Candiens to a 4-3 win over the Boston Bruins on Thursday night in opener of the second round of the Eastern Conference playoffs.

It was the second goal of the night for Subban, who blasted a slap shot from the blue line past Boston goaltender Tuukka Rask just seven seconds after defenseman Matt Bartkowski was called for holding Montreal center Brian Gionta. The Canadiens made quick work for their second power-play goal of the night and a 1-0 lead in the series, which continues Saturday afternoon in Boston.

Right winger Rene Bourque had a goal and an assist and goaltender Carey Price finished with 48 saves, including 15 in overtime.

Rask finished with 28 saves for Boston, which rallied from deficits of 2-0 and 3-2 but never led. The score remained 3-3 after the first overtime. It was a fitting start to the 34th playoff series between the longtime rivals who went into OT for the 38th time in their 171 postseason matchups.

Boston defenseman Zdeno Chara had a great chance to end it about six minutes into the first overtime, poking a rebound behind Price, but the puck bounced across the crease without crossing the goal line.

Price got his right pad out in time to stop an open look from in front by left winger Brad Marchand with about 10 minutes left in the first overtime. Rask answered at the other end with a stop on a one-timer from the crease by center Lars Eller with about six minutes remaining.

Defenseman Johnny Boychuk scored with 1:58 left in the third period, tying it at 3-all and setting up overtime on Boston's third goal of the period. The Bruins rallied from a 2-0 deficit after two periods to tie it on goals by winger Reilly Smith and defenseman Torey Krug.

Montreal defenseman Francis Bouillon put the Canadiens back in front on a goal 7:51 left, but the Bruins continued getting pressure on Price and got one more past him on Boychuk's one-timer slap shot from the blue line off a pass from Marchand.

Marchand ended up with a penalty at the end of the third when he objected to Eller firing a shot at Rask after the horn and delivered a cross check to the Montreal center. Marchand was called for cross checking and Eller for unsportsmanlike conduct.

Bourque's fourth goal of the playoffs put Montreal up 2-0 early in the second period. Montreal pounced on a turnover in the neutral zone and started in on a 3-on-1 with Eller passing the puck back to Bourque for an unscreened wrist shot past Rask.

Subban beat Rask with a high wrist shot from the blue line to give the Canadiens a 1-0 lead with 8:37 left in the first period. Montreal was on a power play after Boston defender Matt Bartkowski was called for tripping 10:05 into the period. It was the first goal of the postseason for Subban, who had five assists in Montreal's first-round sweep of the Tampa Bay Lightning.

NOTES: The Canadiens and Bruins opened their 34th postseason meeting and first since Boston rallied to win in the opening round of the 2011 playoffs in seven games. ... The winner of the first game between Montreal and Boston has gone on to win 27 of the 33 series. ... Montreal RW Brian Gianta was playing in his 100th career playoff game. ... Montreal C Lars Eller got an assist in the second period and has at least one point in all five postseason games for the Canadiens.