Krug and Pittsburgh Penguins forward Patric Hornqvist exited the penalty box at the same time late in the second period of Thursday night's game at TD Garden, and almost instantly they dropped their gloves and started to throw down.
It was Krug's first fight since Nov. 8, 2018.
"Just tensions running high. I've been hit by him many, many times over the years," Krug told reporters when asked about his fight. "So, just something that happens in hockey, came out of the box and we went. It was good. Hopefully, it energized our group a little bit."
The fight clearly energized the Bruins, who finished the game strong and emerged with a 4-1 victory over one of the NHL's hottest teams.
Krug is not the most physically imposing player on the Bruins, but pound-for-pound he's one of the team's toughest players. Whether it's a fight, a huge hit or just setting the tone with an overall physical style of play, Krug is often effective in firing up the home crowd and his teammates.
"I'd like to think that I can do it throughout a game with a big play, or even a hit at times," Krug told reporters. "Over the years, I haven't shied away from doing it in the past. Hopefully, it's a one-and-done thing for me this season, but you never know. I just hope it energized the group in way , shape or form, and it is what is is."