Brandon Bollig and Alex Ovechkin traded goals before a Patrick Kane marker gave the Hawks a first-period lead.
Mikhail Grabovski evened things up but a powerplay goal from Brent Seabrook saw Chicago go into the last 20 minutes leading 3-2.
Grabovski then completed his hat-trick to give the Caps the upper-hand but goals from Brandon Saad, Johnny Oduya and Marian Hossa sealed victory for the Blackhawks.
Montreal enforcer George Parros had to be carried from the ice as the Canadiens began their season with with a 4-3 loss to the Toronto Maple Leafs.
Parros was having his second fight of the evening with the Leafs' Colton Orr when he fell face first to the ice and had to be stretchered off in the second period.
The 33-year-old was speaking as he was taken off but was later taken to hospital.
James van Riemsdyk had given the Leafs a 1-0 lead on the powerplay but Lars Eller and Brendan Gallagher had the Habs 2-1 up at the period break.
Goals from Dion Phaneuf and Mason Raymond had the Leafs ahead going into the third and Tyler Bozak's shorthanded goal rendered Eller's second of the night a mere consolation.
In the Western Conference, Dallas Eakins began his reign as Edmonton Oilers head coach with a 5-4 loss against the Winnipeg Jets.
The scores were tied at 2-2 after a wild first period but the Oilers jumped out into a two-goal lead in the second thanks to goals from Ales Hemsky and Jesse Joensuu.
Michael Frolik reduced the gap to one and a third period strike from Jacob Trouba coupled with a second from Frolik completed the comeback.