Sometimes it takes an anomaly to put things in perspective. Such an anomaly came Friday night when the Bruins, who have been sensational in the third period this season, allowed three unanswered third-period goals to the Sabres, blowing a 2-1 lead and suffering their second regulation loss of the season in the process. 

It was a pretty uncommon performance for the Bruins in a season in which they had been – statistically, at least – the best third-period team in hockey. Just three days earlier, the B's had a three-goal third of their own as they came back from a 3-0 deficit and forced overtime against the Rangers. Brad Marchand's equalizer with 43 seconds left in that game was Boston's 15th third-period goal of the season in 11 games, which put them top-five in the league in third-period goals despite having played less games than the four other teams. 

The five goals the B's had allowed entering Friday's game was the lowest total in the league (though they'd only played 11 games; the Kings were the only other team in the league to play that few entering Friday). Their plus-10 scoring differential in the third period was tops in the NHL.

Then Friday happened, and for the first time this season the B's lost a game that they had led through the first 40 minutes. Tyler Myers tied the game by burying a rebound from a 2-on-1, with Christian Ehrhoff picking up a loose puck in the high slot and flinging a wrist shot past Anton Khudobin to give Buffalo the lead. Cody Hodgson tipped a pass from Myers past Khudobin to give the Sabres some breathing room, capping the game's scoring in a period that saw the Bruins practically sleepwalk offensively. Shots on goal can be a deceiving statistic, but the B’s managed to put only three pucks on Ryan Miller in the third after totaling 29 over the first two periods.

What makes Friday's third period more interesting is the fact that it's the second time in three meetings this season that the Sabres have lit up the B’s in the third period. They scored four goals (including an empty-netter) over the final 20 minutes in Boston on Jan. 31, making the Sabres responsible for seven of the eight third-period goals the Bruins have allowed this season. 

The good thing for the Bruins is that, in most cases, they are dominant in the third. Both times the Bruins have trailed entering the third period this season, they've come back to tie the game (a one-goal comeback against the Rangers in New York and the three-goal comeback against them Tuesday). Additionally, the two losses to Buffalo make for the only instances in which the B’s have been outscored in the third period. 

So why has it happened twice against the Sabres when it doesn’t happen against anyone else? You can give the Sabres credit, for one. Thanks largely to their two wins against the B’s, the Sabres are second in the NHL with 19 third-period goals this season. They also had all the motivation in the world to have a big third on Friday, as they were booed off the ice at the end of a lazy second period. They were lucky it was as close as it was after two, so the combination of their offense (though two of the three goals were scored by defensemen) and their need for two points (they had dropped their previous two games and have had two three-game losing streaks already this season) helped them erase the deficit and send the B’s on their way to Winnipeg without a point.

"We played a desperate team tonight and we weren't prepared to play the third periods against a desperate team," Claude Julien said in his postgame interview on NESN following the game. "We got caught off guard there and it ended up costing us the game." 

Then there’s the fact that Zdeno Chara, despite being arguable the best defenseman in the league, has had quite a few rough moments against the Sabres in his day. He couldn’t get back on the 2-on-1 that led to Myers’ goal, as he was avenging Steve Ott’s hit on David Krejci, which took him out of the play as the Sabres went the other way. Chara was a minus-1 on the night and is now a minus-4 against the Sabres on the season. He’s been a combined minus-7 over the Bruins’ last four losses to Buffalo.  

Bruins players stressed after their comeback against the Rangers Tuesday that they can’t afford to come out of games in the 48-game season without points. With that Rangers game seemingly a lost cause, they buckled down and scored three straight in order to come away with something. They didn’t have the same mindset or execution with the lead entering the third Friday, so perhaps their uncharacteristic performance will provide enough of a reminder of what a bad final period can do.