The home team has won all six games in the series. Game 7 is Saturday in Raleigh, N.C.
Brad Marchand and Charlie Coyle each had a goal and an assist, Derek Forbort, Erik Haula and Curtis Lazar also scored and Tomas Nosek dished out two assists for Boston.
Bruins goalie Jeremy Swayman made 23 saves in his fourth consecutive start. He stopped all 11 shots he faced in the first period.
Andrei Svechnikov scored both Carolina goals, including one on the power play to end the home team’s three-goal run during the final frame.
Antti Raanta recorded 29 saves in the loss.
Carolina trimmed Boston’s lead to 2-1 early in the third, but the hosts broke the game open with goals at the 7:08 and 10:43 marks. Haula netted the first of those tallies, redirecting in Charlie McAvoy’s pass from the slot after the defenceman retrieved a loose puck.