The Black & Gold also had two power plays within a three-plus minute span earlier in the third (9:49 and 13:17 of the frame) - after the Kings had cut the Boston lead to 2-1 - during which they were unable to regain a two-goal lead and put the game away.
"I actually said it to [assistant coach] Chris Kelly on the bench…if we don't score on this second power play, we're going to end up in a tight ball game," said Montgomery.
Boston's bench boss also noted that he sensed a growing frustration on the bench as the Kings - who had allowed six goals in a shutout loss to Buffalo on Tuesday night - smothered the Bruins' offensive attack.
"I thought the Kings did a great job checking tonight," said Montgomery. "They really checked us well and it was hard for us to have any kind of speed on entries or speed on breakouts. So, you give them credit. They're a well-coached team and Todd McLellan has been an elite coach in this league for a long time."
"They have a lot of water bugs, they can play in the corners, they play fast and play hard, and they made it tough on us all night," added Hall. "A team that's had a loss like that going to come out and play hard, try to get a win on the road - and seeing their excitement after the game, they really needed that, they wanted that.
"At the end of the day, that third period, I don't know if they wanted it more or whatever it was, but you're up 2-0 on home ice, it's gotta be a win."
Marchand felt that the Bruins, who slugged out a 4-3 shootout win over the Islanders on Tuesday night, were still trying to find their jump after the long road trip out West and a lack of practice time of late.
"I think we're recovering a bit from that, it's a tough trip to come back from. For all you married [reporters] with kids, it's not easy coming home and taking over, so you kind of get more rest on the road," Marchand said with a smirk.
"It's one of those ones we're going to have to look at and improve upon and get ready for the next one."