Marc Savard scored the tiebreaking goal and Tuukka Rask stopped 36 shots to lead the Boston Bruins to a 2-1 victory over the Toronto Maple Leafs on Monday night.
Nathan Horton also scored for Boston in the finale of 3-0-2 road trip.
Mikhail Grabovski had the Maple Leafs' goal and James Reimer - making his second straight start for Toronto - had 31 saves.
Rask turned away several good chances by former Bruins star Phil Kessel, who has just one assist in nine games against Boston since being traded to Toronto prior to last season.
The only other NHL teams Kessel hasn't scored on during his career - Anaheim, Calgary and St. Louis - are based in the Western Conference so he rarely faces them. The winger has shown recent signs of improvement against the Bruins, scoring the shootout winner in a game last month and looking energized on Monday.
Rask's best save against his former teammate came during the third period after Kessel beat a defenseman and got off a shot from in close.
Grabovski gave the Maple Leafs a 1-0 lead with his 14th goal of the season at 14:08 of the first period after Luke Schenn sent him on a breakaway with a long pass. The Belarussian got his ninth goal in the last 12 games with a nice deke on Rask.
Horton tied it at 7:56 of the second after the puck was cycled around the Toronto zone for some time. The winger sent a shot through a group of players that deflected in off the right post.
Savard got the winner with his second goal of the season at 15:30. He was almost at the blue line when he sent the puck through a screen by Milan Lucic.
It was a big breakthrough for Boston's top line, which hadn't scored in five games since being put together on Dec. 20. Horton and Lucic had just one point between them since mid-December.