CALGARY, AB -- Johnny Gaudreau scored with 1:40 remaining in overtime to complete his hat trick and give the Calgary Flames a 5-4 win against the Boston Bruins at Scotiabank Saddledome on Friday.
Gaudreau was set up by former Bruins defenceman Dougie Hamilton on the game-winner. Hamilton spotted Gaudreau, who trailed the play, in the high slot, and Gaudreau skated in to beat Bruins goaltender Tuukka Rask with a deke.
Mark Giordano and Jiri Hudler scored for Calgary (10-14-2), which has won six consecutive games at home.
Hudler tied the game with 1.2 seconds remaining in the third period when he put a loose puck in the crease over the goal line. After a Boston coach's challenge, review confirmed no goaltender interference occurred.
Brad Marchand had two goals, and Zdeno Chara and Matt Beleskey scored for Boston (13-8-3). The Bruins have lost two straight; their five-game winning streak ended with a 3-2 shootout loss to the Edmonton Oilers on Tuesday.
Boston ends the trip against the Vancouver Canucks on Saturday.
Marchand scored on a shorthanded penalty shot with 1:06 left in the third after Hamilton knocked Marchand's stick out of his hands on a breakaway. Marchand slid a backhand between Karri Ramo's legs to give the Bruins the 4-3 lead.
Gaudreau scored on Calgary's first shot 33 seconds into the game. Flames forward David Jones picked up a turnover from Chara at the blue line and passed to Gaudreau, who beat starting goalie Jonas Gustavsson five-hole.
Giordano put the Flames up 2-0 at 15:55, taking a pass from TJ Brodie before beating Gustavsson short side with a wrist shot from the faceoff circle.
Beleskey tipped Chara's point shot by Ramo with 2:41 remaining in the first to cut Calgary's lead to 2-1. Beleskey, who signed with Boston in July, scored in all five games of a 2015 Western Conference Second Round series to help the Anaheim Ducks eliminate Calgary.
The Flames and Bruins traded three quick goals to start the second period.
Marchand tied the game 2-2 after snapping a shot over the glove of Ramo at 1:36 for his Bruins-leading 11th goal of the season.
Gaudreau scored his second of the game 20 seconds later, taking a pass from Hudler from below the goal line and tucking the puck by Gustavsson's outstretched pad and over the goal line.
Bruins coach Claude Julien replaced Gustavsson with Rask after Gustavsson allowed three goals on 11 shots.
Chara's slap shot through traffic beat Ramo at 2:22 to tie the game 3-3.
Flames defenceman Kris Russell did not play because of an upper-body injury; he is day-to-day. Jones left the game in the first period and did not return because of a lower-body injury.
Hamilton was traded by the Bruins to the Flames this offseason and then signed a multiyear contract with them.