Nathan MacKinnon netted the most breathtaking goal of this year’s NHL playoffs — an end-to-end rush to complete a hat trick and put his team ahead late against the Blues, one that put his wondrous skill and speed on full display.

The Avalanche dropped Game 5 of the second-round series in overtime, however, making what should have been the ultimate highlight more of a footnote in a losing effort.

Such has been the case for much of MacKinnon’s nine seasons in Colorado, a legitimate superstar rarely receiving the national spotlight because his team hadn’t achieved much postseason success.

That all changes beginning Wednesday night at Ball Arena in Denver, where MacKinnon, breakout defenseman Cale Makar and the rest of the rolling Avalanche will host Game 1 of the Stanley Cup Final against the Lightning, the two-time reigning titlists who ousted the Rangers in six games to again represent the Eastern Conference in the championship round.

“This is everything that Nathan has wanted, this opportunity to win the Stanley Cup for his franchise,” longtime Avalanche TV analyst Peter McNab told The Post in a phone interview. “He’s had postseason success personally before, and I think that’s been the most frustrating part for him. He wants this team to win.

“He’s wanted to take those next steps, with his team, because he’s really an intense guy and it was killing him. You could see what they’re doing this year was coming, they were just on the cusp, but it would be goaltending, it would be an injury here or there, always something that kept them from getting to this place.”

MacKinnon, the first-overall pick in the 2013 draft out of Nova Scotia, won the Calder Trophy as the league’s top rookie at 18. Now 26, he later became a three-time finalist for the Hart Trophy, finishing twice as the runner-up in MVP voting.

In five previous playoff appearances during his career, MacKinnon also had posted 28 goals and 69 points over 50 games. His 1.38 points per game in the postseason even was slightly above the best single-season mark during his career of 1.35.

Still, the Avalanche never had reached a conference final during that time, with eliminations in the previous three years in the second round.

“It’s been remarkable to watch his career and how it’s gone,” McNab said of MacKinnon. “The first four years you could feel that he was gonna get there, and the last five years he’s been an absolute superstar in this game.

“I honestly don’t think there’s been anything different about Nathan or his game, he plays at a level that’s really hard to explain.”

Following series victories over Nashville, St. Louis and Edmonton — the latter a four-game sweep against the Oilers and their star center, Connor McDavid — the Avs are playing for the Cup for the first time since they won the franchise’s second title in a six-year span in 2001. MacKinnon has potted a team-high 11 goals along with seven assists in their 14 games.

“It’s not so much that Nathan wants to show anyone that he’s Nathan MacKinnon. He wants to show everybody that he is the on-ice leader of this hockey club. What he does for this team is unreal,” McNab said. “I enjoy watching him every time he plays, but it’ll be fun to see how he and the team respond.

“Because this is different. Tampa Bay, everything you don’t know about the finals, they know. Will the Avalanche, and all the things they do well with their speed and skill be able to beat them?”

Indeed, the Jon Cooper-coached Lightning are four wins away from becoming the first NHL squad to win three consecutive Cups since the Islanders’ four-peat dynasty in the 1980s.

Much of McNab’s question will depend on MacKinnon’s co-stars and supporting cast assembled by GM Joe Sakic, the Hall of Fame center and captain of the Avalanche’s previous Cup-winning teams. That group is led by team captain Gabriel Landeskog and Makar, a Norris Trophy finalist for the second time in his first three NHL seasons.

The 23-year-old Makar — partnered regularly with former Isles defenseman Devon Toews — has followed up an 86-point regular season with a team-best 22 playoff points, including a five-point game in the 6-5 series-clinching win in overtime against the Oilers.

“To me, Makar has really come along to the point that there are now three players in the league that absolutely have ‘it,’ whatever ‘it’ is,” McNab said. “There’s a lot of great players in the game, star players, but for me, it’s McDavid, Nathan MacKinnon and Makar.

“There’s just something extra-special about them that you always want to see what they’re gonna do.”

With eight days of rest entering Game 1, the Avalanche have had time to heal after starting goalie Darcy Kuemper, and key forwards Nazem Kadri and Andrew Cogliano suffered hand injuries against Edmonton. Colorado coach Jared Bednar hasn’t disclosed whether Kuemper or backup Pavel Francouz, who has played the past three-plus games, will start the series opener. Kadri and Cogliano could return later in the series. Forward Brayden Point (upper-body) remains questionable for the Lightning.