The Bruins got the power play in the second extra period when Buffalo's Drew Stafford was caught on the ice as a sixth skater. Satan got a pass from Michael Ryder in front of the net and put it past Sabres goalie Ryan Miller.

Tuukka Rask made 35 saves for Boston and also assisted on Satan's goal.

Ryan Miller stopped 36 shots for the Sabres.

Game 5 is Friday in Buffalo.

Tim Kennedy and Steve Montador scored for Buffalo, which opened a 2-0 lead after two periods. David Krejci and Patrice Bergeron responded in the third period for Boston to send the game into overtime.

Both goalies made stunning saves to keep their teams in the game.

Rask reached out to knock away a puck that even towering defenseman Zdeno Chara couldn't reach, preserving the tie with 11 minutes left in regulation. Miller stopped Blake Wheeler on a short-handed breakaway, then got a glove on a sneaky backhander from Satan early in the first overtime.

In Montreal, Washington pulled away late to beat Montreal and take a 3-1 lead in the Eastern Conference series.

Alex Ovechkin broke a tie with 8:51 left with his second goal of the game and Alex Ovechkin opened the scoring in the first period with Washington's first power-play goal of the series.

Michael Cammalleri and Brian Gionta scored to put the Canadiens ahead, before Mike Knuble tied it 2-2 with just 6.3 seconds left in the second period.

Ovechkin added his second of the game and fourth in three games in the third to put Washington up 3-2. Jason Chimera made it 4-2 less than a minute later. The Capitals got empty-net goals from Knuble with 2:27 left and Nicklas Backstrom with 10 seconds remaining, with Dominic Moore netting for Montreal in between.

Semyon Varlamov made 36 saves to win his third in a row for Washington. Carey Price stopped 32 shots in his first start of the series for Montreal.

Game 5 is Friday in Washington.

In Los Angeles, Vancouver scored four times in a wild third period to beat Los Angeles and even the series 2-2.

Henrik Sedin, Mikael Samuelsson, Sami Salo and Ryan Kesler all scored in the final 12:31 for the Canucks, who rallied from three one-goal deficits and avoided falling to a 3-1 series deficit.

Salo put Vancouver ahead with 7:44 left, but Wayne Simmonds soon answered for Los Angeles. Sedin then got loose on a rush, and the NHL scoring champion put his first goal of the series past Kings goalie Jonathan Quick.

Roberto Luongo made 22 saves, and Daniel Sedin had three assists to help the Canucks win despite yielding two more power-play goals to the Kings.

Christian Ehrhoff and Pavol Demitra also scored for Vancouver. Drew Doughty, Dustin Brown and Anze Kopitar added goals for Los Angeles.

Game 5 is Friday in Vancouver.