There were of course so many "firsts" for the Seattle Kraken in their postseason debut.

First playoff goal for the franchise (and answer to a future trivia question) — Eeli Tolvanen. First playoff penalty — Will Borgen.

Above all, first playoff win and brief celebration.

Alex Wennberg had a goal and an assist, Philipp Grubauer stopped 34 shots and the Kraken made a successful postseason debut by beating the defending Stanley Cup champion Colorado Avalanche 3-1 on Tuesday night.

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The second-year Kraken became the 13th expansion franchise to earn a win in their first postseason game, according to NHL Stats.

"Obviously, we played a good game, getting the first franchise win in the playoffs. But right now this is Game 1," Wennberg said. "Obviously, we are happy about this performance, but we've got to do it again and do it again."

Grubauer was sharp all night against his former team. He frustrated Colorado’s top scorers with one big save after another, while his defense helped neutralize the Avalanche’s blazing speed.

"It’s definitely a weird feeling coming back but also really familiar," said Grubauer, who spent three seasons with the Avalanche before leaving for Seattle prior to the 2021-22 season. "There’s nothing better than playing against your old team in the playoffs."

Nathan MacKinnon didn't mince words when asked what he saw out of Grubauer.

"Nothing," the Colorado forward said.

Mikko Rantanen had the lone goal for the Avalanche, who saw their streak of 10 straight first-round wins come to a halt. It was a string that included two sweeps and dated to 2020.

"Our whole team just wasn’t quite good enough," Avalanche coach Jared Bednar said. "I thought we did some good things. They obviously did more good things."

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Alexandar Georgiev, coming off a career-best 40-win season, made 27 saves.

Game 2 is Thursday in Denver.

The Kraken took a 2-1 lead into the third. They've been virtually automatic when leading after two periods, going 35-1-3 in the regular season. Morgan Geekie sealed it with a tally in the third.

Colorado pulled Georgiev for an extra skater with around 1:35 left but couldn't close the gap.

"Not our best execution tonight, but still had plenty of chances," MacKinnon said. "Now our focus is to move on."

Grubauer benefitted from a little bit of good fortunate. A shot from Evan Rodrigues in the second period glanced off the top of Grubauer's stick and caromed wide of the net. Later, Bowen Byram's wrist shot hit Grubauer's shoulder and then bounced off the crossbar.

"(Grubauer) was great tonight," Kraken forward Yanni Gourde said. "He made the saves and we were able to clean up what was in front of us. He was a stud back there. Good to see him there."

By jumping out to a 1-0 lead, Seattle became the fourth team in the past 20 years to open the scoring in its first-ever playoff game. Tolvanen capitalized on a Colorado turnover to energize the Kraken and stun the crowd.

The lead lasted just over nine minutes as Rantanen tied it up on a pass from MacKinnon. Rantanen had 55 goals in the regular season, the most by an Avalanche player since the team moved to Denver before the 1995-96 season.

Don't sleep on Seattle. Or perhaps do.

"They can do whatever you want," Wennberg said of the doubters. "Obviously it comes down to the belief in the group right here. Everyone is going to have an opinion about the way we play now, but the focus is always going to be on us. We have a belief in this group."

AROUND THE RINK

Avalanche defenseman Jack Johnson was a late scratch with a lower-body injury. He was replaced by Erik Johnson. ... Forward Andrew Cogliano was a scratch. ... Colorado defenseman Josh Manson played in his first game since March 1. He was called for a hooking penalty and later a hold. "He was rusty today," Bednar said. ... Borgen drew the franchise's first playoff penalty when he was called for high-sticking in the second period.

HISTORIC MEETING

This marked the fifth time an NHL franchise made its postseason debut against the defending champion. It also happened with Columbus in 2009 (against Detroit), Washington in 1983 (New York Islanders), Hartford in 1980 (Montreal) and the New York Americans in 1929 (New York Rangers).