Tampa Bay Lightning center Brayden Point (21) breaks out ahead of Boston Bruins left wing Brad Marchand (63 ... gets held by Boston Bruins defenseman Nikita Zadorov (91) as he tries to get a shot on goaltender Jeremy Swayman (1) during the second period ...

The Bruins’ issues compounded. Knies sent the puck down the right-side wall just before Zadorov got in his face. Matthews carried his momentum deep into the Bruins’ end. Because of his speed and size, Matthews overwhelmed Charlie McAvoy on the end boards to win the 50-50 race.

Horvat, who also scored in the first period, broke in alone on goalie Joonas Korpisalo (32 saves) and wristed in the winner from the low slot. It came only six seconds after Ilya Sorokin stoned Brad Marchand at the other end, the rebound triggering Horvat’s game-winning breakaway.