BOSTON -- The Colorado Avalanche lost their seventh straight game when Brad Marchand scored with 57 seconds left in overtime to give the Boston Bruins a 2-1 win at TD Garden on Sunday.
Marchand scored on a wrist shot from the high slot that went off Colorado forward Matt Calvert's left skate.
Nathan MacKinnon scored, and Semyon Varlamov made 33 saves for the Avalanche (22-22-11), whose last three losses have come in overtime, including 4-3 at the New York Islanders on Saturday. They are 1-10 in games decided in overtime this season.
[WATCH: All Avalanche vs. Bruins highlights]
"The last two overtimes for sure have been much better than what we've been doing in the past," Colorado coach Jared Bednar said. "I mean we were going through a stretch there where we were taking penalties right away, where we were getting scored on [during the] first shift. And now we're defending. You can see our conscience from the defending standpoint. I mean tonight's just a wrist shot that happens to hit our guy's foot and changes direction.
"We were playing a decent overtime. We weren't real dangerous ourselves, but neither were they. It seemed pretty safe and they get inside the ice and throw one to the net and it goes in."
Video: EA Overtime Winner: Marchand seals win for Bruins
John Moore scored, and Jaroslav Halak made 35 saves for Boston (31-17-8), which extended its point streak to seven (4-0-3). The Bruins were winless in their past 12 home games against the Avalanche.
"It's a character win," Bruins forward Chris Wagner said. "Tight game, it's a good team. Even though they haven't been doing great, they compete and their fast. And great job by [Halak] too."
MacKinnon scored a goal just as a Colorado power play ended with 33 seconds left in the first period to give the Avalanche a 1-0 lead.
Moore scored on a wrist shot from the top of the left face-off circle to tie it 1-1 at 3:40 of the second period.
"Secondary scoring, right," Bruins coach Bruce Cassidy said. "Johnny Moore, it's nice for him to find the back of the net. It was tough out there today, we didn't have much in the first period, you could see it in the guys that it'd been a long week. They had a similar schedule, so it was going to be tough if we had to chase the game all day.
"So we acknowledged between periods that 'Let's just be patient,' and we did have a good second, got one early enough and wanted to make sure we didn't have to chase it again."
In overtime, Marchand made sure the Bruins completed their sweep of a weekend back-to-back; they defeated the Los Angeles Kings 5-4 in overtime here Saturday.
"[Patrice Bergeron] had his guy beat to the net, so I figured if I could get it into [Bergeron] that he'd be able to walk across and hopefully make a play," said Marchand, who got the puck back from Bergeron before skating to the top of the slot. "But we got a lucky bounce and we'll take it."
Video: COL@BOS: MacKinnon opens the scoring from tough angle
They said it
"Well, three points is not good enough. The last three games, that's what I'm thinking. I'm thinking about … keep losing the games and keep saying, 'Yeah, we'll get the three points from this road trip,' but that's not good enough. We need to find a way to get the wins in overtime." -- Avalanche goalie Semyon Varlamov on Colorado, which ended a three-game trip and is on a season-high losing streak
"It's nice to win a game again, it's been a while. I felt all right against the Rangers (on Wednesday) and against Winnipeg (on Jan. 29). When it goes to OT, 3-on-3, you never know what's going to happen. … Tonight I thought we were going to a shootout again, and when it went in I was happy and I just couldn't believe it at first." -- Bruins goalie Jaroslav Halak, who ended a personal five-game losing streak (0-3-2)
Need to know
The Bruins won in overtime on consecutive days for the second time in their history. The first was March 7-8, 2016, when they won 5-4 at the Florida Panthers and 1-0 at the Tampa Bay Lightning. They are 6-6 in games decided in overtime this season. … Boston had been 0-10-1 with one tie against the Avalanche at home since winning March 30, 1998. … Marchand has eight points (two goals, six assists) in a four-game point streak.
Avalanche: Host the Toronto Maple Leafs on Tuesday (9 p.m. ET; ALT, TSN4, NHL.TV)
Bruins: Host the Chicago Blackhawks on Tuesday (7 p.m. ET; NBCSN, SNE, SNO, SNP, TVAS, NESN, NBCSCH, NHL.TV)
Video: Marchand nets OT winner in Bruins' 2-1 win