OKLAHOMA CITY — Armed with another compelling rookie whose debut was a year in the making, the Thunder had extra reason to be inspired Sunday for the 2023-24 home opener.

All it took was two possessions for Chet Holmgren to receive a humbling jolt and for a booming crowd to lose its edge.

Nikola Jokic easily scored twice over the 7-foot-1 Holmgren in the post to start the game, and that was enough to foreshadow the rest: a 128-95 Nuggets rout guided by Jokic’s 28 points and 14 rebounds, aided by Michael Porter Jr.’s 20-point, nine-rebound contribution and punctuated by clinical defense.

“We know that we have to be a team that can travel, beat the best teams in the NBA on the road, and to do that you have to bring the defense,” coach Michael Malone said. “I felt our defense tonight was outstanding across the board. … The other thing I’m proud of is, winning a championship, the one thing you worry about is thinking we can just show up this year and we’re gonna win. That’s not the case. … After three games, our players are playing with the requisite mindset.”

Jokic bounced back from a nine-turnover outing Friday in Memphis, where the defending champion Nuggets (3-0) won nonetheless to help string together a perfect two-game road trip. Jokic still coughed it up four times in OKC but shot 12 for 16.

“I think how we are playing, that’s the best thing,” Jokic said. “We didn’t lose a step. We are still playing the same way. And the bench is getting a rhythm. I think that’s the most important thing. Wins? Great. We want to win, but I think the style of the play and how we are playing, that’ll give it longevity.”

The bench was excellent for the second straight game, with Christian Braun and Peyton Watson combining for 30 points on 20 shots.

Oklahoma City (2-1) has become a popular underdog pick in the NBA to make another big leap this season after its 16-win improvement in 2022-23 — accomplished even without the No. 2 overall pick Holmgren, who was injured — but the Thunder’s first loss had “Welcome to the pros” written all over it for the promising big.

Holmgren amassed 13 rebounds and seven blocks two days earlier in Cleveland. Against Jokic and the Nuggets, he had four boards and no blocks. Try as he might to match the muscle of a two-time MVP, Jokic was completely unbothered by his matchup whenever he touched the ball. In the third quarter, Holmgren was readying himself to defend Jokic in the low post by lowering his head into Jokic’s midsection. When Jokic’s arm swung, Holmgren crumpled from contact to his face.

The questionable offensive foul call drawn by his positioning was about the only way he or anyone else for Oklahoma City could defend Jokic.

“He’s a really talented guy, but this is his first year. He’s still learning everything: the game, how quick it is, where is (he at) an advantage, where is (he at) a disadvantage,” Jokic said. “I think he needs experience. I think he needs to be a little bit fatter, to be honest. But yes, he has a talent that is unique.”

When Jokic was just starting in the league, he told The Post, it wasn’t a matter of trying to add more fat: “I didn’t have an option,” he said.

Holmgren was able to punch back offensively with 19 points — the upside is obvious given the ability of someone with his length to attack off the bounce — but the Thunder’s best player was kept in check. Shai Gilgeous-Alexander shot 2 for 16 from the field against Kentavious Caldwell-Pope (already 3-0 as winner of the DPOG chain) and a Nuggets defense that was rotating cohesively, closing out cleanly and rebounding robustly. Within eight minutes, Denver was out-rebounding OKC 14-5 and had scored eight second-chance points to set the tone.

At the center of those fundamentals was Porter, who continued to do everything he’s done well early this season, while also making shots for the first time. His shot-taking confidence grew throughout the first quarter, so Malone staggered him with the second unit alongside Jamal Murray (19 points, eight assists) in the second quarter.

“My ankle is just starting to feel better. I’m starting to feel more balance in my shot,” Porter told The Post. “And then I didn’t play all preseason. I didn’t really get to finish training camp, so it’s just being out there and getting the feel for it again.”