BOSTON — Everything Nathan Horton does in the 2011 Stanley Cup playoffs is a first for him, just like when a rookie makes the NHL for the first time.

The playoff neophyte can now add game-winning goal in double-overtime to his list of firsts.

The power forward’s goal 9:30 into the second extra session at TD Garden ended Game 5 of the Eastern Conference quarterfinal series with Montreal with the Bruins skating off with a 2-1 win and a 3-2 edge in the series.

“I saw the rebound, we had control of the puck, and I saw the rebound come out,” said Horton. “It was like it’s in slow motion. It was just sitting there. I’ll tell you, it felt good to put that in the net. Obviously winning the game, it was a pretty special moment.”

Game 6 is Tuesday night in Montreal.

Here’s a quick glance at the box score:

•Tim Thomas finished a grueling night with 44 saves on 45 shots.

•After the first two periods went by scoreless, Brad Marchand scored his first playoff goal to get Boston on the board. Jeff Halpern then tied the score for Montreal with just 6:04 left in regulation.

•Patrice Bergeron led the Bruins with six hits.

•Everyone can stop complaining about Milan Lucic’s lackluster play. The forward assisted on the game-winning goal, fired eight shots on net and blocked four shots.