Dennis Seidenberg broke a tie with 1:04 remaining in the third period, and the Boston Bruins continued their success in Ottawa with a 2-1 win over the Senators.
Daniel Paille scored the other goal for the Bruins, who notched their 11th straight road victory against the Senators. They have won 12 of 13 overall in this series.
Anton Khudobin made 27 saves, helping Boston snap a two-game losing streak and a three-game slide as the visitor.
"We haven't been playing great hockey lately and we had to fight through it. We asked our guys to battle through it, we knew it wasn't going to be pretty," said Boston head coach Claude Julien.
Robin Lehner also stopped 27 shots for Ottawa, which had its winning streak halted at three games.
The Bruins struck late in the second period to erase a 1-0 deficit. Paille fired a wrister from the right circle that beat Lehner on the short side with 1:22 remaining.
Seidenberg's first goal in 30 games put Boston in front. Patrice Bergeron won a faceoff in the offensive zone and Zdeno Chara dished to Seidenberg, who let go a slap shot from the right point that eluded Lehner.
"Against this team you always have to play 60 minutes," said Ottawa head coach Paul MacLean. "At the end of the second period and the end of the game, we stopped playing for a little bit and that ends up being the difference."
Kaspars Daugavins put the Senators on the board with his first goal of the season. Mika Zibanejad carried the puck into the Boston end before slipping the puck to Daugavins and Khudobin couldn't get his glove up quick enough to deny the Ottawa forward at the 4:55 mark of the middle frame.
Ottawa defenseman Sergei Gonchar recorded an assist in a ninth straight game, a new team record ... The Senators opened a five-game homestand and fell to 10-2-3 at Scotiabank Place this season.