"It's great tonight," said Malkin, who has 10 points in his past three games (seven goals, three assists). "We played quick. We used our legs. We understand each other… We enjoy playing. We are having fun right now. We understand we have four great lines."
WATCH: [All Capitals vs. Penguins highlights]
Phil Kessel scored twice; Carl Hagelin, Patric Hornqvist and Bryan Rust each had a goal; and Matt Murray made 29 saves for Pittsburgh (29-21-3), which has won four straight and is 9-2-0 in its past 11 games.
"This weekend, we have some big games," Kessel said. "We started off pretty good."
Alex Ovechkin had two goals and an assist, and Braden Holtby made 27 saves on 33 shots for Washington (30-16-5), which has lost four of its past six games (2-2-2).
"I thought we had some stretches where we were fine," Capitals coach Barry Trotz said. "I thought we were pretty resilient. We were chasing the game and got it tied up. At the end of the day, we just gave them a few too many odd-man rushes and we lost the special teams war."
Pittsburgh was 3-for-4 on the power play; Washington was 0-for-3.