Boston won for the 12th time in 13 contests and ended the Maple Leafs' three-game winning streak. The Bruins also moved past Toronto into first place in the Northeast Division.
Chara scored on a wrist shot with 4:30 left in the second period to give Boston a 3-2 advantage. Lucic produced a power-play goal late in the first that forged a 1-1 tie and he tipped in a shot by David Krejci for a 5-3 lead with 4:39 to go in regulation. Lucic has 10 goals for the season.
Brad Marchand added an empty-net goal to account for the final score.
Jonas Gustavsson allowed five goals on 38 shots in suffering the loss. Tim Thomas made 33 saves and improved his record to 12-4.