The 18-year-old left winger had a shot on goal at 16:59 of ice time.
“It was great and I’m sure it’s going to get better every time, like when the season starts (Oct. 12), but it was great,” Slafkovsky said. “Sure it was faster, but it’s little things. I’ll get used to it.
“I won a couple pucks, I lost a couple. I can be better. I know myself, I can play better, I can skate faster and shoot more.”
It was each team’s first preseason game.
Tomas Tatar and Graeme Clarke scored for the Devils. Mackenzie Blackwood started and made 15 saves on 16 shots for the Devils. Nico Daws came on midway through the second period and made five saves.
Cole Caufield scored for the Canadiens. Jake Allen made 18 saves in 29:18, and Cayden Primeau made 11 saves on 13 shots in relief.
Caufield scored on the power play at 12:32 of the first period to give the Canadiens a 1-0 lead.
Tatar tied it 1-1 with a power play goal at 16:07 of the second period.
Clarke scored at 14:03 of the third period to make it 2-1.
New Jersey center Nico Hischier left the game after the first period due to cramps. Hischier, who is the Devils’ captain, had a shot on goal with 6:24 left in ice time.
Video: Tatar, Clarke clean sheets in 2-1 pre-season win
Panthers 4, Predators 3 (OT): Aleksander Barkov scored with one second left in overtime to give the Florida Panthers a 4-3 win against the Nashville Predators at Bridgestone Arena in Nashville in the first preseason game for each team.
Barkov’s shot from the left circle on the run went wide.
Paul Maurice made his Florida coaching debut in the first of the two split games between the teams. Nashville won Game 2 4-0.
Ryan Lomberg, Eetu Luostarinen and Kai Schwindt scored, and Aaron Ekblad and Santtu Kinnunen each had two assists for the Panthers. Barkov had an assist, and Sergei Bobrovsky made 10 saves on 12 shots in 31:45 before being replaced by Mack Guzda, who made 12 saves.
Juuso Parssinen had a goal and an assist for the Predators. Connor Ingram made 10 saves on 12 shots in 31:17 before being replaced by Devin Cooley, who made 18 saves.
Nino Niederreiter had an assist in his Predators debut after signing a two-year, $8 million ($4 million average annual value) contract on July 21.
Ryan Johansen tied the score at 3-3 for Nashville with 5:25 left in the third period on a deflection.
Luostarinen gave Florida a 1-0 lead with a shorthanded goal with 43 seconds left in the first period when he scored on a 2-on-1.
Schwindt made it 2-0 at 3:41 of the second period before Parssinen cut it to 2-1 at 4:42. Roland McKeown tied it 2-2 at 11:45.
Lomberg put the Panthers ahead 3-2 at 2:11 of the third on a rebound to the left of the net.
Rangers 4, Islanders 1: Igor Shesterkin stopped all 14 shots he faced midway through the second period, helping the New York Rangers to a 4-1 win against the New York Islanders at Madison Square Garden in New York.
It was each team’s first preseason game.
K’Andre Miller scored a shorthanded goal and Brennan Othmann had two assists for the Rangers. Dylan Garand made nine saves in relief of Shesterkin, who played 31:41 after winning the Vezina Trophy last season and being voted the NHL’s top goaltender.
Robin Salo scored for the Islanders, who lost in Lane Lambert’s first game as manager. Semyon Varlamov allowed four goals on 20 shots in 31:15 before being replaced by Jakub Skarek, who made 15 saves.
Jimmy Vesey gave the Rangers a 1-0 lead on the power play at 10:51 of the first period with a high-angle shot over Varlamov’s left shoulder from the right side. The 29-year-old forward, who played his first three NHL seasons (2016-19) with the Rangers, is in training camp on a professional tryout contract.
Chris Kreider made it 2-0 with a rebound at 15:48.
Miller extended the lead to 3-0 with four seconds left in the period when he scored off a feed from Othmann, who chased down a loose puck in the corner after an Islanders turnover.
Zac Jones pushed it to 4-0 with a layup at 11:41 of the second period.
Salo scored at 16:10 for the final 4-1.
Video: Kreider, Miller score 4-1 preseason win
Blues 4, Stars 0: Josh Leivo had two goals and an assist for the St. Louis Blues in a 4-0 win over the Dallas Stars at the American Airlines Center in Dallas.
Logan Brown had a goal and an assist for St. Louis, which has won its first two preseason games. Thomas Greiss made 10 saves in the first period, and Colten Ellis made 23 saves to complete the shutout.
Anton Khudobin made 11 saves on 13 shots in the opener, and Jake Oettinger made 13 saves on 15 shots for Dallas in his first preseason game.
Brown scored his third goal in two games off a rebound at 13:13 of the first to make it 1-0.
Leivo made it 2-0 at 19:04, then scored again at 11:54 of the second period for a 3-0 lead for the Blues.
William Bitten scored at 13:01 of the third period for the 4-0 final.
Predators 4, Panthers 0: Forward Matthew Tkachuk was held scoreless in his Florida Panthers debut, a 4-0 loss to the Nashville Predators at Bridgestone Arena in Nashville.
It was the second of two games split between the teams. Visiting Florida won Game 1 4-3 in overtime.
Tkachuk, who had a shot on goal at 18:13, was acquired on July 22 in the trade that sent forward Jonathan Huberdeau and defenseman MacKenzie Weegar to the Calgary Flames.
Ryan McDonagh had an assist in his Predators debut, and Matt Duchene and Mattias Ekholm each had two assists. Kevin Lankinen stopped all 13 shots he faced before being replaced midway through the second period by Yaroslav Askarov (12 saves).
Spencer Knight started in goal for the Panthers and made 19 saves on 20 shots in 29:56. Alex Lyon made 15 saves in relief.
Filip Forsberg put Nashville up 1-0 at 14:23 of the first period. It was his first game since signing an eight-year, $68 million contract (average annual value of $8.5 million) on July 11.
Cody Glass made it 2-0 at 8:01 of the third period from the right wing off a pass from Duchene for a power play goal.
Colton Sissons made it 3-0 at 13:30 when he finished off a breakaway with a backhand, and Tanner Jeannot tipped in a McDonagh shot at 17:12 for the 4-0 final.
McDonagh was traded to Nashville by the Tampa Bay Lightning on July 3.
NHL.com freelance correspondent Sean Farrell contributed to this report