Almost 15 years have passed since Milan Lucic blew up goalie Ryan Miller on Garden ice, an infamous hit that would help send the Buffalo Sabres into their Dark Ages. On Sunday in Game 4 at the Garden, the Sabres finally got a little payback.

With a chance to tie the best-of-seven series on Causeway Street, the Bruins were embarrassed by the Sabres thanks to a comically bad first period that put them in a hole from which they had no chance to extricate themselves. The B’s took a well-deserved 6-1 loss and are now down in the series 3-1. They will be down to their last out of the season when they face the Sabres in Game 5 on Tuesday at Keybank Center.

“Man to man in here, if we’re not f—- embarrassed with what just happened, I don’t know what to say,” said Charlie McAvoy, who along with his partner Jonathan Aspirot was minus-4. “It’s not over after three games. We have everything to play for here and we know we’re such a better team than what we did today.”

“Embarrassed” was the operative word after the game.

The B’s had won 29 games on Causeway Street this season, tied with the Carolina Hurricanes for most home Ws in the NHL. But they couldn’t win either of their home games in the series and, if they don’t get their game in order before Game 5, they will have played their last game at the Garden for the season.

Meanwhile, the Sabres, after 14 years out of the playoffs, are on the verge of their first playoff series win since 2007.

The Bruins’ have suffered more dramatically painful losses on home ice in recent memory. The Game 7 Stanley Cup Final loss in 2019 comes to mind. But it’s hard to think of one that was less competitive. The Sabres’ forecheck made mincemeat of the Bruins’ defense in the first period.

How do you explain a team not being ready to compete and/or execute in such a big game?

“I can’t,” said coach Marco Sturm. “I don’t know. I really don’t know. I could feel a little bit of it in Game 3, for no reason, and definitely today. If you’re a Boston Bruin and playing at home, you should be very excited going into a playoff game. We didn’t, so I can’t really answer that question right now.”

The first period was a theater of the macabre for Bruins fans, at least those fans who hadn’t sold their tickets to Sabres fans.

They fell down 4-0 and it could have been much worse than that. The B’s were outshot 19-5 and they were charged with 10 giveaways, which felt like some charitable counting from the stat crew.

The first goal against at 4:17 was a harbinger of things to come. McAvoy’s simple D-to-D pass didn’t connect with Aspirot and the puck drifted dangerously toward the blue line. One of their best defensive forwards, Fraser Minten, jumped in to help. But after he collected the loose puck, Minten’s reverse bank pass went right to Alex Tuch, who fed Peyton Krebs for the one-timer goal. The Sabres’ fans in the building popped loudly and it was the beginning of a long afternoon for the home team.

The Sabres made it 2-0 seconds after a Buffalo power play ended at 7:10. Hampus Lindholm’s soft clear attempt was knocked down and then Ryan McLeod fed Josh Doan at the top of the crease for a redirect.

On the third goal, Jordan Harris, inserted into the lineup for Mason Lohrei, coughed up the puck upon Doan’s stick check and it went right to Zach Benson, who moved in and tossed an in-tight backhander at Jeremy Swayman, who made the initial stop but the rebound bounced off Benson and trickled in.

Sturm was in no mood to discuss what wrong from an X-and-O standpoint.

“I can’t even going into the rush game, the O-zone, D-zone, I really can’t,” said Sturm. “In all areas, we were just behind. Emotionally, if you’re not ready for it…it didn’t matter. So I don’t talk about little details because they were not there today.”

Sturm called his timeout at that point at 9:15 after the Benson goal.

“We were just hurting and I had to stop this, first of all,” said Sturm. “Message-wise, there’s a few things I had to address and the other thing, you had to wake them up. For some reason, two games in a row, we were just totally flat. In a playoff game. That just can’t happen.”

But happen it did, and the timeout couldn’t stop the hemorrhaging.

Buffalo made it 4-0 at 14:24 when Aspirot knocked a Sabre into Swayman, leaving the goaltender flailing. Bowen Byram used the opportunity to score his third of the series into the shortside.

Predictably, the Bruins fans that were in the house booed their team off the ice at the of the first.

To make matters worse, the B’s were without Viktor Arvidsson to start the second after he had taken a high hit from Mattias Samuelsson late in the first.

Pride kicked in a little bit in the second period and the B’s finally spent a little time in the Sabres zone, especially late in the period. But Alex Lyon (22 mostly easy saves) made the stops he needed to, when the Sabres didn’t block the shots in front of him. The B’s earned one power play late in the second but they did nothing with it and they still faced the daunting four-goal deficit to start the third.

For the most optimistic of Bruins fans, even their hopes were doused when Beck Malenstyn scored on a deflection early in the third, followed up quickly by a Tuch goal, both goals coming off turnovers.

Sturm then gave Swayman the mercy pull, which frankly could have happened after the disastrous first. The netminder appeared to let his teammates have it before he went down the tunnel.

Only a Sean Kuraly goal with 39.9 seconds left, with the B’s killing a Nikita Zadorov major after he cross-checked and punched Rasmus Dahlin, kept the B’s from suffering their first shutout of the season.

That didn’t change the overriding feeling utter failure one iota.

“A waste of opportunity,” said David Pastrnak, who took nine shots, only one of which got through to the net. “Unacceptable. We expect more from ourselves. We are better than that. You can’t show up like that, in an afternoon game. The first period is so f— important…to show up like that as a team is unacceptable.”

We will see on Tuesday what, if anything, they can do about it.