CALGARY -- The Calgary Flames lost for the first time in 11 games, 5-2 to the Boston Bruins at Scotiabank Saddledome on Wednesday.
The Flames (39-27-4) were one victory shy of setting the franchise record for longest winning streak. The Atlanta Flames won 10 straight from Oct. 14-Nov. 3, 1978.
"It was in our heads, obviously, in the back of our minds," Calgary captain Mark Giordano said. "But at this time of year, again, every win, every loss … they're so important and you have to learn not to get too high and not to get too low."
WATCH: All Bruins vs. Flames highlights
Brad Marchand scored his NHL-leading 36th goal, David Pastrnak scored twice, and backup goalie Anton Khudobin made 21 saves for the Bruins (38-26-6), who have won four games in a row.
"We knew that they play great hockey," Pastrnak said. "For us, honestly we try to stick with our plan and focus on us and do the job, what we talked about, and it worked today. Obviously, it feels really good."
Boston, which is 12-3-0 since Bruce Cassidy took over as coach for Claude Julien on Feb. 7, is four points behind the Montreal Canadiens for first place in the Atlantic Division and three behind the Ottawa Senators for second.
Alex Chiasson and Dougie Hamilton scored, and Chad Johnson made 27 saves for Calgary in his first start since Feb. 24. Brian Elliott, who won nine of 10 games during the streak, did not dress because he was ill.
"I haven't played a lot, and when you come in there, you don't want to be the guy to be in the net when it ends, that's for sure," Johnson said. "I didn't feel great about my game, so that part is disappointing."
Video: BOS@CGY: Marchand capitalizes on misplay by Johnson
Calgary trails the Anaheim Ducks by two points for second place in the Pacific Division and leads the fourth-place Edmonton Oilers by one point.
"You take winning for granted a lot," Flames forward Kris Versteeg said. "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."
David Backes gave the Bruins a 3-2 lead at 11:03 of the second period after leaving the game in the first because of an injury.
"It's maybe scary at the time, but you get back with the training staff and rub it and kiss it and make it feel better, and you're able to return to the game," Backes said. "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."
Matt Beleskey ended a 21-game goal drought dating to Nov. 19 when he scored to put Boston ahead 4-2 at 3:36 of the third, and Pastrnak scored his 30th goal into an empty net to make it 5-2 with three seconds left.
Chiasson scored 9:23 into the first period to put the Flames up 1-0, but Pastrnak tied the game 2:24 later.
Marchand scored 6:04 into the second period to put Boston up 2-1 after Johnson mishandled a dump-in from the neutral zone, and Hamilton scored 1:10 later to tie it 2-2 when his dump-in from just inside center ice got past Khudobin.
Goal of the game
Backes took a pass from David Krejci on a 3-on-2 and snapped a shot over Johnson's glove from the top of the left faceoff circle.
Video: BOS@CGY: Backes snipes pretty goal from the circle
Save of the game
Johnson slid across his crease to get his left pad on Marchand's wraparound 58 seconds into the third period.
Highlight of the game
Bruins defenseman Adam McQuaid forced a turnover at the Boston blue line that resulted in a 2-on-0 that Beleskey finished on a setup by Ryan Spooner.
Video: BOS@CGY: Beleskey buries Spooner's nifty dish on rush
Unsung performance of the game
Bruins defensemen Brandon Carlo and Kevan Miller each blocked a shot in the final five minutes of the game with the Flames on the power play and trying to make it a one-goal game.
They said it
"It was a big one for us. We need to focus on ourselves and stay with our play, and I think we did a great job in the third." -- Bruins forward David Pastrnak
"It wasn't so self-inflicted. I'm not going to stand here and throw my guys under the bus because they won 10 in a row and lost one at home. Boston was better than us. Boston was dialed in. They were better than us tonight. We just didn't have enough to take on another good team. It is disappointing, but at the same time, you're not going to win every game. We understand that. It's going to be how we react coming back. We have good character in there. We'll react appropriately." -- Flames coach Glen Gulutzan
Need to know
Pastrnak has four goals in his past four games and 14 points (five goals, nine assists) during a 10-game point streak. …Chiasson's goal gave Calgary 12 players with 10 or more goals for the first time since 1990-91, according to Sportsnet. … Flames center Matt Stajan earned his 400th NHL point on Chiasson's goal.
Bruins: At the Edmonton Oilers on Thursday (9 p.m. ET; SNW, NESN, NHL.TV)
Flames: Host the Dallas Stars on Friday (9 p.m. ET; SNW, FS-SW+, NHL.TV)
Video: Pastrnak's pair leads Bruins past Flames