After a scoreless first period, Vanek opened the scoring a minute and a half into the second period. Sabres forward Cody Hodgson took a pass from Jason Pominville along the right wing boards, carried it into the offensive zone, where he then made a cross ice pass over to Vanek who one-timed it past Bruins’ goalie Tuukka Rask.
However, the Bruins fought back with a goal by Rich Peverley and then two more by Brad Marchand to take a 3-1 lead within the next 9 minutes of play.
The tides turned 15:45 into the second period when the Bruins got tacked with two penalties, one on Milan Lucic for boarding and the other on Zdeno Chara for holding.
On the ensuing 5-on-3 power play, Thomas Vanek tipped in a saucer pass from defenseman Christian Ehrhoff with 3:15 remaining in the second period to bring the Sabres within one.
Then, with the Sabres still up a man, Thomas Vanek made a great pass while falling to Tyler Ennis in front of the net, who shot it past Rask on the short side and tied the game at 3-3 with 1:41 remaining in the period.
The Bruins would go back in front on a goal by David Krejci a minute and 45 seconds into the third period, but Alex Sulzer tied the game back up at four for Buffalo a mere 43 seconds later on a wrist shot from the top of the left circle after a nice pass from Mikhail Grigorenko.
The Sabres then took a 5-4 lead a little over four minutes later with a goal by Cody Hodgson after a nice pass from Vanek on a 2-on-1 rush.
Vanek wasn’t done there, as he scored an insurance goal with a minute and a half remaining in the game, giving the Sabres a 6-4 lead. Vanek stole the puck in the neutral zone starting a 2-on-0 rush with Jason Pominville. Then, instead of passing to Pominivlle, Vanek triple-deked in front of the Boston net and backhanded a shot over Tuukka Rask, giving him the eighth hat-trick of his NHL career and capping off a five point night.
An empty-net goal by Pominvile with 14 seconds remaining then capped off the game, ensuring the Sabres their first victory since Jan. 21 against the Toronto Maple Leafs.
Despite giving up four goals, Ryan Miller had a strong night in net for the Sabres stopping 38 of 42 shots that the Bruins threw at him, including a few stellar saves in the third period that helped the Sabres secure the victory.
After becoming the first team this season to defeat the Bruins in regulation, the Sabres move to 3-3-1 on the season, and will travel to Montreal for an afternoon game against the Canadiens on Saturday, Feb. 2.