What happened: Cole Caufield scored on a breakaway to put Montreal ahead 4-0, per the Canadiens' account of the play. Boston goaltender Jeremy Swayman's night ended on the goal.
Why it matters: A four-goal deficit with the starter out leaves the opponent chasing the game on the back-up's watch.
By the numbers: Caufield scored 50 goals last season.
What to watch: Montreal now looks to protect the four-goal lead through the third period.