Garnet Hathaway scored the deciding goal with 2:28 left in the second period, and the Boston Bruins held on for a 2-1 victory over the visiting Tampa Bay Lightning to clinch the Atlantic Division title on Saturday afternoon.
The Bruins (56-11-5, 117 points) have won six consecutive games.
Hathaway has scored three goals since joining the Bruins, two of which have been go-ahead tallies.
Patrice Bergeron netted Boston's first goal, extending his season-long point streak to five games. The Bruins captain has eight points in that span.
Linus Ullmark made 11 of his 26 saves in the third period, improving to 11-1-0 in his last 12 starts.
For the Lightning (42-26-6, 90 points), Victor Hedman scored the lone goal and Andrei Vasilevskiy was credited with 32 saves.
The loss was Tampa Bay's fourth in a row.
A fight between Hathaway and Tampa Bay's Patrick Maroon just nine seconds in set the tone for a penalty-filled first period. The teams combined for 28 penalty minutes and 27 hits, while both goals were scored during special-teams situations.
Boston took a 1-0 lead at 6:46 as Brad Marchand's shot from an off angle on the left side deflected in off Bergeron for a power-play goal.
Hedman leveled the score with a shorthanded tally 9:30 into the first, taking a quick drop pass from Pierre-Edouard Bellemare and ripping a shot from above the left circle.
Hathaway buried the Bruins' go-ahead goal by slamming home the rebound of Matt Grzelcyk's shot from the point while parked directly in front of the Tampa goaltender.
Grzelcyk's assist was his 20th of the season, tying a career-high mark.
David Pastrnak nearly scored his 50th goal of the season when Grzelcyk sprung him on a breakaway with less than six minutes remaining in regulation, but his shot sailed just over Vasilevskiy's net.
--Field Level Media