Backstrom gave Washington the lead midway through the second, and Chiasson added to it with 12 minutes left when he took two swipes at a puck in the crease to get it past Khudobin.
Alex Chiasson scores pair of goals as Capitals beat Bruins again →
"We can't rely on the same guys to bring offense every night," Chiasson said. "We need other guys to chip in. Lars' line tonight was our best line. Some nights, some guys are going to be hotter than others. That's just the way it goes."
Capitals' offense solves home woes in win over Islanders →