Montreal Canadiens defenseman Alexei Emelin found that out the hard way when he squared off with the Bruins defenseman in the second period of Sunday night's game at the TD Garden.
The sequence started with Emelin cross-checking Bruins forward Tyler Seguin in the neutral zone. Chara did not like that one bit.
The 6'9" defenseman immediately went after Emelin to stick up for his teammate, like every good captain would do. Chara received 17 PIM for the fight: two for an instigator, five for fighting and a 10-minute game misconduct.
Seguin went into the locker room following the hit by Emelin, but the young star quickly returned to the game.
It was the first fight of the season for Chara. He fought four times last season (T-most in his Bruins career) after dropping the gloves just once in 2009-10 and 2010-11. The bout was Emelin's first as an NHL player.
Boston and Montreal played an intense second period with the Bruins taking a 3-2 lead going into the final 20 minutes. Just a few minutes prior to the bout between Chara and Emelin, Bruins forward Milan Lucic and Canadiens forward Brandon Prust also fought.
This kind of exciting, physical action is just what you would expect from the NHL's best rivalry.
Nicholas Goss is an NHL Lead Writer at Bleacher Report. Follow him on Twitter. He was a credentialed reporter at the 2011 Stanley Cup Final and 2012 NHL playoffs in Boston. Nick has also covered the Bruins since the 2010-11 season.