Los Angeles had a chance to extend the lead when it was awarded a penalty shot at 10:24. But after Guillaume Brisebois was called for hooking Adrian Kempe on a breakaway, Demko made the save when Kempe tried to go five-hole.
"A lot of times [Demko] makes us look good," Miller said. "When we play good in front of him, it takes the stress off him, those high-quality looks. … Don't want to give up 40 shots every night, but when you do, he only gives up two."
Pettersson then tied it 2-2 at 11:33 of the third period, scoring on a wrist shot from the right face-off circle seven seconds into a power play.
Vancouver was 1-for-1 on the power play after going 0-for-5 with the man-advantage in a 3-2 loss at the Arizona Coyotes on Thursday.
"The power play, obviously, was a big goal for us. Some good kills (2-for-2)," Canucks coach Rick Tocchet said. "Yeah, we had a couple meetings on our special teams that really helped us."