Hall gave Boston a 1-0 lead at 7:53 of the second period, snapping a wrist shot past Copley's blocker from the high slot during a delayed penalty.
"At the end of the day, that third period, I don't know if they wanted it more, whatever it was, but you're up 2-0 on home ice. It's got to be a win," Hall said."
Marchand made it 2-0 at 10:02 with a power-play goal. David Pastrnak worked his way deep into Los Angeles' zone before finding Marchand, who drifted into the right face-off circle and shot short side over Copley's left shoulder.
Boston had three power-play opportunities in the third, including one that extended into overtime, but couldn't get another shot past Copley.
"I still thought that we were going to win," Marchand said. "But those [late power-play opportunities] are the ones you have to capitalize on. When you get a late one there, especially in overtime, we kind of swung that one away, so that was frustrating."