Sandin made it 2-1 at 8:22, scoring over Blomqvist’s right shoulder from a sharp angle at the left face-off dot.
Mangiapane tied the score 2-2 at 6:04 of the second period on a feed from Jakub Vrana on a 2-on-1 rush.
Later in the period, Blomqvist stopped Tom Wilson on an odd-man rush, and Lindgren made a sprawling pad save on Rickard Rakell in front.
“We probably knew we needed this one,” Rust said. “I think in the locker room we weren't too happy with how that second period went. We kind of knew that we just needed to go over the boards, kind of hit the reset. The game was tied and go out there and win a period.”
NOTES: Friday’s game marked the 70th time that Sidney Crosby and Alex Ovechkin played against each other in their NHL careers. Crosby has 91 points (31 goals, 60 assists) against Washington, and Ovechkin has 67 points (37 goals, 30 assists) against Pittsburgh. … Ovechkin’s five-game point streak (six goals, five assists) was snapped. … Capitals forward Dylan Strome had his five-game point streak (one goal, nine assists) snapped. … The Penguins have points in six straight visits to Capital One Arena (5-0-1) and are 7-1-1 in their last nine road games against the Capitals. … Rust played 18:27 and was plus-2 in his return after missing five games with a lower-body injury.