Put this one under the category of “ugly.”

You know those oft-quoted lines about not putting a team away or allowing a team to hang around or what happens when a hot goaltender takes over a game

Well, all of three were front and center at TD Garden on St. Patrick’s Day night.

In what should have been a cakewalk game, the Bruins, gave Buffalo life in the third period after 40 minutes of a snoozer before the crowd adorned in a sea of green.

Boston held Buffalo to 10 shots on net through two periods.

“As the game goes on, you’ve got full control,” head coach Claude Julien said after. “You’ve got a one-nothing lead and you just can’t seem to get that second goal. Those are the dangerous situations to be in when a team hangs around that long and eventually they’re going to get a break somewhere and they did.”

With Carl Soderberg in the penalty box, Rasmus Ristolainen wristed one from the point off Matt Bartkowski’s skate past Niklas Svedberg at 1:32 of the third period to knot the score at 1-1.

Svedberg got Julien’s call in net for the 15th time — spelling relief for Tuukka Rask’s after 58 overall appearances. Rask, given the rare night off for purported “general soreness” was replaced on the bench by Jeremy Smith, who got the call up Rt. 95 from Providence for the second time this season.

Owners of the worst overall record in the league in both major categories — total points at 45 and regulation and overtime wins at a paltry 12 into their 70th game, the Sabres came to town after two spirited losses — to Washington in a shootout Monday night and a previous 2-0 loss to the Rangers, the second goal in an empty net. Add that Buffalo was winless in its last seven games, goaltender Anders Lindback was 0-10-2 in a Buffalo uniform this season, and it all added up to a sure two points for the Bruins.

At 4-1-0 in their last five, and 7-2-1 last 10, Boston was looking to retain its five-point lead over Ottawa. One quiet stat, however, sat in the background Tuesday night: the Bruins had never swept the Sabres in a season series in team history.

“When you go out there and just go out there and play and compete hard and obviously no pressure you become a pretty good team and that’s what they are right now,” Julien said after morning skate. “The last two times we beat them it took overtime so we’re certainly not in a position to come out and take them lightly.”

Well, the Bruins did take Buffalo — very — lightly.

And it cost a valuable point in the playoff race as the Senators downed the Hurricanes in OT to climb within four points of the Bruins; the two play Thursday in Ottawa.

The Bruins gave Svedberg the first two periods off, while Loui Eriksson gave Boston its only lead of the game 10 minutes into the first period when Adam McQuaid played pool with a cue shot off the back dasher that bounced back out next to a befuddled Lindback. Eriksson, parked in neutral next to the crease, drove the puck to twine for his 18th goal and 40th point. Soderberg also credited with an assist.

In overtime, both teams had glaring opps to win it, especially Boston when Chris Kelly launched a howitzer from the point that Lindback saved, stretched from post to post. It was a highlight-reel save among several of his 44 total.

The shootout was another round of blanks with Patrice Bergeron, Brad Marchand and Torey Krug all contributing to Boston’s woeful 14% shootout stat. Meanwhile, Tyler Ennis buried one past Svedberg in Round 1 — and that was all, folks.

If the Bruins miss the playoffs by one point, it may well be the St. Patrick’s Day game that gets the nod as the reason why.

“We had chances,” Julien said. “We had shots and if we’re not going to find ways to bury goals then you’ve got to look at yourselves in those kinds of situations. We know that, so we’ve got to pick up our socks here and not feel sorry for ourselves because we feel we got short changed here tonight and understand what’s at stake.”

We all know what’s at stake with 12 to go.

When asked about traffic in front of the Buffalo goal to generate more offense, Julien said: “Yeah, there was. Sometimes maybe too much.”

There is also too much playoff traffic building behind the Black and Gold.