It was Arvidsson's fifth hat trick in the NHL and his second straight three-point game. He had three assists in a 4-3 shootout win at the Columbus Blue Jackets on Sunday.
Henri Jokiharju and Elias Lindholm each had a goal and an assist, and David Pastrnak had three assists for the Bruins (43-24-8), who have won six of seven, including four straight. Joonas Korpisalo made 13 saves.
Wyatt Johnston had a goal and an assist, and Jamie Benn and Matt Duchene scored for the Stars (44-19-12), who are 1-4-2 in their past seven and finished a four-game road trip 1-2-1. Jason Robertson had two assists, and Jake Oettinger made 17 saves.
Khusnutdinov put the Bruins up 1-0 at 9:58 of the first period. Jokiharju's slap shot from the right point deflected off Stars defenseman Esa Lindell in the slot to Khusnutdinov, who put a wrist shot between Oettinger's pads.
Arvidsson made it 2-0 at 18:51, tapping in Pastrnak's backdoor pass from below the goal line behind Oettinger as he battled in the crease.
Benn cut the deficit to 2-1 at 4:49 of the second period after sending a backhander in front from the right corner. The puck bounced off Wyatt Johnston back to Benn, who went skate-to-stick and stuffed the puck under Korpisalo's right pad.
Duchene tied it 2-2 at 16:53 when he collected a loose puck from behind the net and lifted a shot high to the blocker side at the right post.
Lindholm's power-play goal gave Boston a 3-2 lead just 13 seconds into the third period. He took a backhand pass from Pastrnak in stride into the offensive zone and buried a wrist shot from the top of the right circle past Oettinger's blocker.
Jokiharju made it 4-2 at 5:51 with a wrist shot from the high slot to the glove side for his first goal with the Bruins.
Arvidsson scored an empty-net goal at 16:23 for a 5-2 lead.
Johnston brought Dallas to within 5-3 while on the power play at 19:02, lifting a backhand shot over Korpisalo's blocker from in front.
Arvidsson scored a second empty-net goal at 19:47 to complete the hat trick and secure the 6-3 final.
