NHL: Michael Frolik's pair, Valimaki's first lift Calgary Flames over Boston Bruins

Michael Frolik scored twice and rookie defenseman Juuso Valimaki scored his first NHL goal as the Calgary Flames beat the Boston Bruins 5-2 on Wednesday night.

Goalie Mike Smith was sensational in making 24 saves to backstop the Flames in their return home following a three-game road trip.

Frolik, who was a surprising healthy scratch in the club's previous outing, opened the scoring at 5:34 of the first period, one of three goals the Flames scored in the period.

The veteran winger finished a three-way passing play that featured Matthew Tkachuk and Mikael Backlund with a shot into an open net, a rare occurrence against Boston's best line of Patrice Bergeron, Brad Marchand and David Pastrnak.

After Johnny Gaudreau doubled Calgary's lead with his 100th career goal at the 15:20 mark of the period, Valimaki --, Calgary's 2017 first-round draft choice -- sent a long wrist shot into the top corner at 16:08.

Bergeron put the Bruins on the board at 2:40 of the second period, but Frolik notched his second of the game, and third of the season just 52 seconds later.

Marchand again pulled the visitors within a pair with a tally at 13:45 of the second period -- a goal that Bergeron set up -- but the Bruins couldn't solve Smith again.

Tkachuk rounded out the scoring with an empty-netter in the final minute. Backlund also had a two-point night on a pair of assists.

The win came with a cost to Calgary as Gaudreau left the game midway through the third period after absorbing a late hit from Boston defenseman Charlie McAvoy, who was assessed an interference penalty.

Boston goalie Tuukka Rask, who made 24 saves, lost to the Flames in regulation for the first time. Rask went into the game with a 6-0-3 career record against Calgary.