Jarry made a left-pad save on Milan Lucic's shot on a 2-on-0 with Dillon Dube at 17:45.
"Just to play the shot, wait as long as I can," Jarry said. "I've had, I think, two in the last three games. I think every one I've played differently at this point. I was just making sure I was playing the shot and getting over there as quick as I can when he passed it."
Jarry made consecutive saves on Andrew Mangiapane and Matthew Tkachuk 7:07 into the third, and Malkin, who missed the past two games because of illness, reached the milestone with an empty-net goal to put Pittsburgh ahead 3-1 with 1:58 remaining.
Malkin joined Mario Lemieux (690), Sidney Crosby (451), and Jaromir Jagr (439) as the only players in Penguins history to score 400 goals.
"Those are special names," Malkin said. "They're legends, for sure. I want to be top too. I want to play my top-level game. It's a good number, but I want more, for sure. I feel it right now. I work hard every day, and I hope I play five, six more years here with the Penguins, and we'll see what's going on after. To be with Jagr, Lemieux, Crosby is amazing."
Kris Letang scored into an empty net from behind the Penguins goal line to make it 4-1 with 1:38 left.