CALGARY, Alberta -- A heart-and-soul effort by David Backes helped the Boston Bruins extend their winning streak to four games in a row.

After crashing hard into the boards late in the first period, Backes returned in the second to score the game-winning goal as the Bruins beat the Calgary Flames 5-2 on Wednesday at the Scotiabank Saddledome.

"It's maybe scary at the time, but you get back with the training staff and they rub it and kiss it and make it feel better and you're able to return to the game," said Backes. "The way guys were battling and playing for each other, I wanted to make sure that if there was a chance that I'd get back out there and try to help our team win another game."

Boston coach Bruce Cassidy was impressed with the bounce-back effort by Backes.

"It's going to take a little more than that to keep him out," said Cassidy, whose team will try to keep their winning streak going against the Oilers in Edmonton on Thursday. "When it happened, I think we were all concerned. You never know what's going on at the far end of the ice.

"He got some treatment in between periods and told us he was going to give it a try and it worked out well for us. He scored a big goal for us and played some key shifts for us down the stretch. Hopefully there's no residual effect tomorrow, but we'll worry about that then."

David Pastrnak had two goals, including one into an empty net with 2.1 seconds remaining, for the Bruins (38-26-6), while Brad Marchand and Matt Belesky also scored.

Making his first start since March 4, Boston goalie Anton Khudobin made 21 saves to record his fourth straight win and improve his record to 5-5-1.

Alex Chiasson and Dougie Hamilton scored for the Flames (39-27-4), who tied a franchise record with their 10th straight victory on Monday when they beat the Pittsburgh Penguins 4-3 in a shootout.

"You take winning for granted a lot," said right winger Kris Versteeg. "Each time you win in this league is really tough so you should be excited about it. You can dwell on certain things, but if you're winning you can't be angry. This is a tough league to win in and if you take wins for granted then it's going to be an awfully long year."

The Atlanta Flames also won 10 games in a row from Oct. 14 to Nov. 3, 1978, before relocating to Calgary two seasons later.

Due to an illness to goalie Brian Elliott, Chad Johnson made his first start in net for Calgary since Feb. 24 and finished with 27 saves.

"I didn't feel very good, to be honest," said Johnson, who was disappointed he couldn't help the Flames set a franchise record. "It was tough. Some weird bounces, some bad goals. At times I felt good but I definitely wasn't at my best."

Chiasson scored his 10th goal of the season at 9:23 of the first period when he cut out from behind the net before tucking a shot past Khudobin.

Pastrnak replied for the Bruins at 11:47 when he skated in on right wing and wristed a shot from the faceoff circle through Johnson's legs.

Johnson then let in another soft goal at 6:04 of the second when he mishandled Colin Miller's dump in from the red line. Marchand did a good job to sneak in behind Calgary defenseman Matt Bartkowski to retrieve the loose puck before backhanding it into the net for an easy goal.

Khudobin had a gaffe of his own 70 seconds later when Hamilton's harmless-looking wrist shot from outside the blue line found its way into the net over the goalie's right pad.

Backes put the Bruins up 3-2 at 11:03 when he took a pass from David Krejci and wired a shot to the top corner, glove-side behind Johnson.

The Bruins went up 4-2 at 3:36 of the third when Beleskey converted a feed from Ryan Spooner to capitalize on a two-on-zero opportunity.

NOTES: The Flames recalled G Jon Gillies from the AHL's Stockton Heat on Wednesday and he served as G Chad Johnson's back-up. ... The Flames scratched C Curtis Lazar, C Freddie Hamilton and D Rasmus Andersson, while D Michael Stone missed his third straight game with an upper-body injury. ... Bruins C Ryan Spooner, who missed the past three games due to a concussion, made his return to Boston's lineup. ... The Bruins scratched D John-Michael Liles, D Joe Morrow, C Austin Czarnik and LW Peter Cehlarik, while C Tim Schaller missed his third straight game with a lower-body injury. ... Bruins RW David Pastrnak extended his point-scoring streak to 10 straight games (five goals, nine assists). ... Flames C Matt Stajan had an assist on RW Alex Chiasson's first-period goal for his 400th career NHL point.