WASHINGTON — As the replay of the Washington Capitals’ fourth goal flashed across the videoboard, the applause in Capital One Arena grew louder. One hat dropped onto the ice, then another, then another as fans squinted to see who last touched the puck.

There was no doubt about Alex Ovechkin’s first two goals, stunning shots from his favorite spot at the left faceoff circle. The third required a few extra looks; Evgeny Kuznetsov’s shot was tipped before going into the net, but was it Ovechkin’s stick that got a piece of the puck? Replay confirmed it was indeed Ovechkin’s goal, giving him hat tricks in back-to-back games to open the season.

Ovechkin added a fourth goal in the second period, and the Capitals cruised to a 6-1 win against the Montreal Canadiens in their home opener. It was a historic night for Washington. Ovechkin is just the fourth player to open the season with back-to-back hat tricks, and he’s the first to accomplish that feat in 100 years, as three players did it in the first NHL season.

Is this a perfect start to the season?

“Well, obviously, yeah,” Ovechkin said. “It’s a fun time when you play like that and your line feeling it. It’s fun to play.”

More history came on the Capitals’ sixth goal when Devante Smith-Pelly’s shot bounced off forward Nathan Walker and into the net. Walker became the first Australian to play in an NHL game when he took his first shift Saturday night. With his family in the stands, Walker also notched his first goal.

It was initially credited to Smith-Pelly, who immediately recognized the shot deflected off Walker. He asked for the puck as a keepsake for Walker, and when the scoring change was later announced, Walker’s mother, Ceri, stood and wildly waved an Australian flag, cheering with the rest of the arena. Ovechkin skated over the bench to give Walker a few taps on the helmet.

“It was amazing,” Walker said. “As a kid, you’re always thinking you’re going to play in the NHL one day and be there. I just tried to take it all in and enjoy myself.”

Goaltender Braden Holtby quietly recorded 38 saves in a home opener few will forget. The last time the Capitals played a game that counted here, it was a 2-0 loss to the Pittsburgh Penguins in Game 7 of the teams’ second-round playoff series. The disappointment from the postseason exit hung over the team and the fan base throughout the summer, but Saturday night’s rout was another step in moving forward.

isabelle.khurshudyan@washpost.com

twitter.com/ikhurshudyan