There’s no substitute for experience. And the shorthanded Nets got a hard-earned lesson at the hands of the reigning champion Raptors in Monday’s playoff opener.

The Nets got floored early, and even after getting up off the deck and back in the fight they never really hurt the Raptors. They lost 134-110 in Game 1 of the Eastern Conference’s first round, an up-close look at how a champion plays.

“They’re champions and have played on the big stage before, and seemed like they were trying to deliver an early message,” said Nets interim coach Jacque Vaughn. “I did like the way our group responded after halftime and accepted that first punch: The rounds will continue.”

The Nets got bloodied in Round 1, and looked on the way to a TKO. They trailed by 33 in the first half before showing some pride in the second, cutting it to eight.

Eight, but no closer.

“They ended up jumping out on us, ended up getting up by 30 at one point,” Joe Harris said. “They were definitely the more aggressive team on both ends of the ball.”

And flat out the better one, having won 12 of their past 13 games dating back before the pandemic.

Fred VanVleet had a game-high 30 points, 11 assists and hit 8 of 10 from deep. In some cases, 30-feet deep. Serge Ibaka had 22 points and seven rebounds off Toronto’s bench, while Pascal Siakam added 18 points and 11 boards.

Meanwhile, the Nets looked befuddled early against Toronto’s long, athletic defense. Timothe Luwawu-Cabarrot had 26 points off the bench, while Harris added 19 points on 3 of 5 shooting from deep.

The Raptors used hedges, traps and doubles to turn Caris LeVert (15 points, 15 assists, six boards) from a scorer to a facilitator. The tactic worked.

“They were trapping all of my isos, mid-post, top, all my ball screens,” LeVert said.

“Guys are going to have to make plays. That’s how it’s probably going to be for a majority of the series,” Harris said. “Caris is our best offensive player, and teams are going to try to get the ball out of his hands.”

The Nets will have to get LeVert out in transition, like they did in the second half. Because playing like they did in the first is a recipe for disaster.

The Nets fell behind 10-2 right out of the gate, missing five of their first six shots and committing a pair of quick turnovers. They were down 37-20 after the first quarter, and in a 68-35 hole after VanVleet drilled consecutive 3s.

At that point, the Nets were shooting just 3 of 17 from deep with eight turnovers, harried into poor passes and worse shot selection. They did at least settle in on defense, which sparked their own transition offense.

The Nets mounted an extended 47-22 run that bridged the half. They held Toronto to 27.8 percent shooting with seven turnovers in that spurt, getting Luwawu-Cabarrot on the break and LeVert finding Harris in early offense.

“[The comeback] was huge for us. We know the type of game we have to play,” LeVert said. “We know the type of mentality we have to play with on offense. And defensively, play with more force. … The first quarter they were just coming off freebies, making shots like they were just warm-up practice shots. We can’t play that way.”

Brooklyn got within 90-82 on Luwawu-Cabarrot’s 3 with 2:06 left in the third. But when Toronto opened it back up to 119-102 with 3:54 to play, Vaughn capitulated and emptied his bench — although not before his players had been taught a valuable lesson.

“This is the defending champion, and it’s not going to be easy. Every single game is going to be hard,” Luwawu-Cabarrot said. “We know the recipe now, and we know how we have to play, and that’s how we’re going to do it. … That’s the way we’re going to start every single game.”