Bruins lose their last game before Winter Classic, falling to Sabres in overtime at Garden

In the second period, Sabres goalie Ukko-Pekka Luukkonen denied Brad Marchand, who scored in the third to give the Bruins a 3-2 lead.John Tlumacki/Globe Staff

With the Winter Classic some 49 hours after Saturday’s puck drop against the Sabres, Bruins coach Jim Montgomery wasn’t worried his team would look ahead.

“Usually I’d be very concerned about that, but not with this group,” he said. “They’re very, very professional.”

They put on a good show, but squandered a third-period lead and lost their final game of 2022. Before the ball dropped in Times Square, the Bruins dropped the ball on Causeway Street.

The Sabres escaped with a 4-3 overtime win thanks to Alex Tuch and Dylan Cozens, who combined for the winning goal.

Cozens, who tied the game with 1:37 left in regulation, stripped the puck from Patrice Bergeron and fed Tuch on a 2 on 1 the other way. The ex-Boston College forward’s shot ramped off Bergeron’s stick and eluded Jeremy Swayman at 3:53 of extras.

Swayman (four goals on 25 shots) was not at his sharpest. On the tying goal, he couldn’t hold onto Cozens’s shot from the wing, set up by a drop pass from Tuch. But he wasn’t the only Bruin lamenting one that slipped away.

“I had the game on my stick a couple times,” said David Pastrnak (1-1—2), who saw his empty-net try blocked by Rasmus Dahlin moments before the Sabres backliner sent a long pass to Tuch for Cozens’s tying goal. He also couldn’t lift a forehander over a sprawling Ukko-Pekka Luukkonen amid the Bruins squandering a full two minutes of a 5 on 3 late in the third period.

They had that opportunity when JJ Peterka bloodied Brandon Carlo with a high stick (four minutes), and Ilya Lyubushkin chopped Jake DeBrusk. The Bruins, who finished 1 for 5 on the power play, had 10 shots on goal and 12 attempts during the 4:04 of power-play time.

With 3:44 left, the two-man advantage gone and his team firing blanks, Montgomery called timeout. He drew up a play for the final 1:09 of Peterka’s double-minor for high sticking. He wanted to rest his best players and change the mojo, but felt afterwards he should have done so sooner.

“Should have called timeout when the 5 on 3 happened,” Montgomery said. “We hadn’t had one in a while, and we were very disorganized. Our puck movement and our spacing was not the way we wanted it to be. I’ve got to take responsibility for not calling timeout there and then to end the game.”

Pastrnak, Bergeron, and Brad Marchand looked as if they had done so. The Bruins were up, 3-2, and the TD Garden crowd was about to ring in the New Year with another win at home.

Instead, the Sabres (18-14-2) became the third team this year to earn two points in Boston. The Bruins (28-4-4) did, however, finish the 2022 portion of their schedule without a regulation loss on Causeway Street (18-0-3).

Given what’s ahead — a Sunday practice at Fenway Park, and Monday’s Winter Classic — the Bruins weren’t laboring over Saturday’s result.

After 40 minutes, the Sabres hadn’t broken away on the scoreboard — they held a 2-1 lead — but they were scooting through the middle of the ice and bearing down on Swayman.

The Bruins, who fell to 19-0-2 when scoring first, had a one-goal edge on Pastrnak’s first-period strike.

Pastrnak scored his 25th of the year in trademark fashion, stepping into his left-circle office and slamming a one-timer past Luukkonen (37 saves) at 13:09 of the first. The work before was wizardly, with all four teammates — David Krejci, Pavel Zacha, Carlo, and Hampus Lindholm — touching the puck within four seconds of Krejci setting up No. 88 with a cross-ice feed.

Only Auston Matthews (37) had more 5 on 5 goals in the calendar year 2022 than Pastrnak (32).

The Bruins had several chances to extend the lead. Bergeron’s line, when on the ice with Lindholm and Charlie McAvoy, were too much for the Sabres to handle. Luukkonen seemed to seek relief behind him, subtly knocking off the net during one dominant sequence from Boston’s best.

On a power play at 13:40 of the first, the Bruins leaked a shorthanded breakaway and Swayman stopped Payton Krebs. At the other end, Marchand shot into Luukkonen’s pad on a patient setup from Bergeron below the dots.

After Buffalo made the kill, Tage Thompson did what he does: stickhandled his way into a goal. The Sabres had a quick-strike 3 on 2 after Tuch harassed Connor Clifton into a turnover in the left circle. Matt Grzelcyk was guarding the back post and was unable to handle Thompson, the NHL’s breakout star of 2022-23, using his 6-foot-7-inch reach to tuck one around Swayman’s pads.

In the opening minutes of the second, the Bruins nearly took a 2-1 lead on a breakaway. Instead, the Sabres did.

First, Krejci sent Zacha in alone. The winger zipped the puck through the closing pads of Luukkonen, but the netminder, atop his crease, got just enough of it to send it careening to the corner.

Moments later, Lindholm tried to break up a stretch pass from Lyubushkin, but Tuch fought it off, skated in and ripped one high blocker past Swayman at 2:03.

Bergeron scored his 15th goal on the power play at 5:16 of the third, finishing a Marchand feed from the corner. Marchand’s five-hole breakaway finish at 12:25 put the Bruins up by a goal.

“Disappointing finish,” Marchand said. “We had that game. We had our hands all around it.

“So that’s kind of on us. We could be much better in that situation. We’re not going to dwell on it. We got a point. We’ve got a great opportunity ahead of us.

“We’re going to have a lot of fun. It’s an exciting time. Everyone has a ton of family here. We’re all looking forward to getting out there tomorrow and skating and getting another win.”