Bruins defenseman Zdeno Chara, right, checks Capitals winger Joel Ward (42) into the boards during the third period. (Winslow Townson/ASSOCIATED PRESS)

Each visit to TD Garden comes with a warning: Get wrapped up in the Boston Bruins’ rough-and-tumble game, engage them in fights and other extracurricular activities after the whistle, at your own peril.

Saturday afternoon the Washington Capitals were swept up in the cauldron on Causeway Street. Pushed around and bullied by the big, bad Bruins, who are as skilled at agitation as they are at scoring goals, the Capitals fell, 4-1. It was Washington’s fourth loss in the past five games, each one causing additional damage to the team’s already slim playoff hopes.

“It’s their game, it’s not ours. We have to understand that. I know it’s hard, but it’s one of the strengths of that team,” Capitals Coach Adam Oates said. “That’s part of what they bring, that team over there. You’ve got to beat them on the scoreboard and keep the game close.”

Boston was in control of the game from the outset thanks to a series of defensive miscues by the Capitals. Turnovers by Troy Brouwer and Jack Hillen led directly to the Bruins’ first two goals, by Nathan Horton and David Krejci. Then, a missed assignment made it 3-1 on a tally by Andrew Ference before the contest was halfway over.

Instead of working their way back from the deficit the Capitals got caught up in shoving after whistles, in chirping at their opponent, in jawing at fans clad in black and gold and ultimately in the style of hockey Boston plays. The distractions prevented them from threatening to rally.

The Washington Post’s Dan Steinberg, LaVar Arrington, Mike Wise and Jonathan Forsythe discuss the Capitals’ standings halfway through the shortened season. (Post Sports Live)

With 18.9 seconds remaining in the second period, the Bruins’ Brad Marchand grabbed the neck of Mike Ribeiro’s jersey and started throwing punches, leaving the Capitals’ center no choice but to fight for the first time in his 764-game NHL career.

The last time Ribeiro, who wasn’t made available to reporters after the game, fought was during the 1998-99 season when he was playing in Canadian juniors. As he served his five-minute major penalty, Ribeiro started mouthing off at a Bruins fan who was mocking him by making a crying face.

Seconds after that fracas was sorted out, Matt Hendricks dropped the gloves against Boston winger Nathan Horton. “I was yelling at him,” said Horton, who recorded a goal and a pair of assists. “Three times I yelled at him and he didn’t look at me. And then, he just sprinted at me.”

The Bruins didn’t take kindly to Horton, a top-line player with a history of concussions, having to fight. So in the third period, after a power-play goal by Rich Peverley gave them a comfortable 4-1 lead, Boston’s more natural scrappers sought retribution.

Off a faceoff with less than 10 minutes remaining in the game, Bruins heavyweight Shawn Thornton began challenging Hendricks, following him all over the ice and out into the neutral zone. It was there that Boston defenseman Adam McQuaid came up from behind, cornering Hendricks and all but forcing him to choose which foe to fight.

“I let him know I was there too, and I guess he had his pick,” McQuaid said. “We don’t like to see our top line fight, give in to stuff like that. So it’s one of those things where you’ve got to stick up for your teammates.”

Hendricks split his right hand open in the fight and needed medical attention, but it’s unclear how much harm was done. He wasn’t made available to reporters and Oates didn’t have an update on Hendricks’s status.

It was clear, however, that the Capitals didn’t appreciate how their teammate was ganged up on.

“That’s the biggest joke I’ve ever seen, in my opinion. The fact that they let those guys corner a guy like that,” said Karl Alzner, who said all the Capitals can do is return the favor: “Go after one of their guys. . . . We’re probably not going to do that because we’re not that kind of team. But that’s the only thing you can do.”

Fights are one thing, but the Capitals were clearly thrown off their game. The usually composed Hendricks yapped and pointed at fans while heading down the tunnel to the dressing room for treatment after his second fight. Oates said the Capitals have to learn to not let the tone of the game or an opponent impact how they play.

“There’s going to be nights during the course of the year that there’s going to be some fights and the game is not as fluid, it’s more choppy,” Oates said. “It shouldn’t affect us.”