As Johnny Gaudreau’s overtime game-winner whizzed past Tuukka Rask and into the Boston Bruins’ net, the usually reserved Dougie Hamilton broke out an emphatic celebration.

He had plenty of reason to.

Hamilton, the former Bruins defenseman dealt to the Calgary Flames in perhaps the most surprising deal of the NHL offseason, wasn’t much of a factor for the first 58 minutes of Friday night’s 5-4 Flames win. He made a nice sliding play to break up a shorthanded 2-on-1 in the first period, but other than that, the 22-year-old defenseman largely was limited to supporting-character status.

That changed when, with the score tied and 1:06 remaining in regulation, Hamilton turned the puck over to ex-Bruins teammate Brad Marchand and then slashed him with his stick, preventing a shorthanded breakaway but giving Marchand a penalty shot.

The Boston winger slotted his chance between the legs of Flames goalie Karri Ramo, and with one minute to play, Hamilton appeared destined to go down as the goat in his first game against the team that drafted him.

But Calgary rallied. Jiri Hudler jammed a loose puck past Rask with 1.2 seconds to play, tying the score at four goals apiece and forcing overtime. Given new life in the extra session, Hamilton capitalized, receiving a pass in the neutral zone and dropping it back for Gaudreau, who fired it home for his third goal of the night.

After managing just five points through his first 24 games with the Flames, Hamilton now has two (a goal and an assist) in his last two.

“Kind of an unfortunate play (on the penalty shot),” he told reporters after the game, via the Calgary Herald. “I’m just thankful we tied it up there and ended up winning. Definitely a weird one, playing against my old team.”

Thumbnail photo via Candice Ward/USA TODAY Sports Images

Thumbnail photo via Calgary Flames defenseman Dougie Hamilton pushes Boston Bruins winger Brett Connolly.