Joonas Donskoi scored a tiebreaking power-play goal with 13:23 remaining after an offensive zone penalty by Boston's Jimmy Hayes and the San Jose Sharks beat the Bruins 3-2 on Tuesday night.
Brent Burns helped set up Donskoi's goal and scored one of his own, tying Sandis Ozolinsh's franchise records for goals and points in a season by a defensemen.
Melker Karlsson also scored as San Jose won consecutive home games for the first time in two months to move within one point of Anaheim for second place in the Pacific Division.
James Reimer made 21 saves on his 28th birthday for his first home win with San Jose.
David Krejci, Loui Eriksson scored for the Bruins, who had their streak of seven straight games with a point snapped. Boston fell one point behind Florida in the Atlantic Division. Tuukka Rask made 24 saves.