Bruins 5, Sabres 2
Dougie Hamilton also scored for the Bruins, who won their third game in a row. Chad Johnson made 14 saves for Boston (6-2-0).
Cody Hodgson and Nikita Zadorov scored for the Sabres (1-9-1). Ryan Miller had 29 saves.
The Bruins held a 3-2 lead at the second intermission.
Krug gave the Bruins a 4-2 lead at 4:17 into the third period, then increased it to a three-goal advantage five minutes later on a snap shot from the left circle.
The game took an ugly turn six minutes into the third when Boston winger Loui Eriksson was injured after receiving a hit to the head from Buffalo enforcer John Scott. Eriksson was helped to the Boston locker room following the hit and did not return.
Scott received a match penalty.
- - -
Senators 6, Red Wings 1
Jason Spezza and Bobby Ryan each scored twice, and the Ottawa Senators beat the Detroit Red Wings.
The Senators spoiled Daniel Alfredsson's first game against the team for which he played 17 seasons and captained for 13 before signing a one-year, $5.5 million free agent contract with Detroit in July.
Eric Gryba and Jared Cowen also scored for Ottawa (4-3-2).
Erik Karlsson and Kyle Turris each had two assists and Craig Anderson made 27 saves.
Todd Bertuzzi scored for Detroit (6-4-1), who lost their third straight. Jimmy Howard made five saves on eight shots before being replaced by Jonas Gustavsson with 5:46 left in the first period. Gustavsson stopped 17 shots.
Ottawa's Craig Anderson made 31 saves for the win.