The Maple Leafs are off to the second round of the Stanley Cup playoffs after a hard-fought 4-2 victory over the Senators in Game 6 of their opening-round series.

Max Pacioretty, who had been promoted to the second line earlier in the day, scored the winning goal on a wrist shot with 5:39 remaining on Thursday.

The 36-year-old forward missed more than half the games in the regular season due to injury and at times was scratched even when healthy.

“This means a lot,” Pacioretty said. He also had an assist. “You keep on playing [and practicing] because you want to pitch in.”

Pacioretty’s goal answered a score by Ottawa’s David Perron that had tied the contest at 2-2 with 7:20 remaining.

Auston Matthews and William Nylander also scored for Toronto, Nylander twice, including an empty-netter with 19 seconds remaining. Goalie Anthony Stolarz, making a sixth consecutive start for the first time in his career, had 21 saves.

“We are happy to be in the second round,” Nylander said. He celebrated his 29th birthday on Thursday. “Now our focus is on Florida.”

The Stanley Cup champion Panthers are next up. They won their first-round series over Tampa Bay in five games on Wednesday. The first two contests will be at Scotiabank Arena.

This is only the second time in nine years that the Maple Leafs won a post-season series. In 2023 they defeated Tampa Bay in six games in the first round but were then eliminated by Florida. Thursday’s triumph is only Toronto’s second in its last 15 opportunities to eliminate an opponent during the playoffs.

The Senators, who won all three regular-season meetings with the Maple Leafs, lost the first three encounters in the first-round matchup but then won the next two. They proved to be a worthy rival in this Battle of Ontario. overtime.

Ottawa had hoped to become just the fifth team in NHL history to come back from a 3-0 deficit, joining the 1942 Maple Leafs, the 1975 New York Islanders, the 2010 Philadelphia Flyers and the 2014 Los Angeles Kings.

The last time the Maple Leafs won two rounds was in 2002 when they beat the Islanders and Senators before they fell to the Carolina Hurricanes in a third-round defeat.

This was the fifth time the teams met in the post-season since 2001. Toronto has won each time.

Matthews found the back of the net with a long wrist shot with 70 seconds remaining in the first period to break a scoreless tie. The goal, his second of the playoffs, came with assists from Mitch Marner and Nylander.

Nylander then scored 43 seconds into the second period after a turnover in Ottawa’s end. Pacioretty recorded the assist.

The Senators, who reached the post-season for just the second time in nine years, proved to be a tough and resilient opponent. So much so that Toronto general manager Brad Treliving was pacing back and forth in the press box hallway during the intermissions.

Ottawa captain Brady Tkachuk tipped in a shot by Thomas Chabot with 12:32 left in the second period to cut Toronto’s lead to 2-1. It was Tkachuk’s fourth goal and seventh point in six games and brought the crowd to its feet inside Canadian Tire Centre.

The Maple Leafs last claimed a Stanley Cup in 1967. This incarnation of the Senators are still in pursuit of their first, since joining the NHL in 1992-93.

Earlier in the day both teams talked about the challenge at hand.

“We have to have that same mindset that we have had of win-or-go-home,” Tkachuk said following the morning skate. “It‘s the same message as the past couple of games: We have to leave it all out there, physically, mentally, emotionally, and the game usually takes care of itself.”

Back at home again, the Senators got to play in front of a pulsating crowd that has been starved for success. It was ornery and loud. Ramones loud.

The Maple Leafs outscored their opponent 15-14 through the first five games. Their most-counted-upon scorers -- Nylander, Matthews and Marner -- had just one goal apiece however.

They all had huge moments in Game 6.

Matthews went 16-6 in face-offs as well.

“He led us tonight,” Craig Berube, the Toronto coach, said.

The biggest night belonged to Pacioretty. This his 16th NHL season and he is still trying to claim his first Stanley Cup.

“He had a huge goal,” Berube said. “He did a real good job. He’s a veteran guy who has been around and he came through for us.”

Pacioretty contemplated quitting at times this year.

“I had a lot of conversations with my family and others,” he said. “I thought I was done.”