Laughton scored the 1-2 goal at the end of the first period, played by Erik Gustafsson, among others.
Then he put the equalizer at the beginning of the second and then 6-4 at the end of the third period.
Sean Coutier accounted for two goals for Philadelphia.
Philadelphia's Swedish defender Robert Hägg scored his first goal of the season when he thundered in 3-3 in the second period.
Sixth of all time
The match initially looked to be Ovetchkin's show.
He put 1-0 and 3-2 for the home team, his fourth and fifth goals of the season and in total in the NHL he has now scored 711. In total, with playoff goals, he has scored 780 and thus knocks down the legend Phil Esposito from sixth place in the NHL- the shuttle of history.
The Russian also had a good performance, after scoring an eight with the puck between his own legs, to Tom Wilson's 2-0 goal.
And he also passed to Nicklas Bäckström who made 4-4 with his back to the goal.
Bäckström also got two assists in the match.
Poor goalkeeper game
Washington fired 37 shots, but the team's goalkeeping game was downright lousy.
Vitek Vanecek conceded four of 14 shots (71.4 in save percentage) and was substituted at the end of the second period.
Craig Anderson was not much better, conceding two on eight shots (75 in save percentage).
Philadelphia's last goal was in an empty cage.