ORLANDO, Fla. — The Nets have become allergic to the fourth quarter, and they conjured up another late collapse against the Magic.

The Nets blew a lead in the final period on Monday, falling 101-89 at Amway Center, a sixth straight loss.

The defeat saw the Nets fall behind Orlando (17-20) into the eighth and final playoff spot in the Eastern Conference. But if they don’t fix the way they’re floundering this regular season, they won’t have to worry about any postseason.

“We didn’t get stops when we needed to in critical moments, we didn’t get rebounds when we needed to in critical moments, we didn’t get the 50-50 balls we needed to in critical moments, and a lot of that’s on the first unit,” Joe Harris said. “We have to do a better job executing down the stretch, making shots down the stretch.”

About that stretch …

After rallying to take a 78-76 lead, the Nets (16-19) suffered through a three-minute scoreless drought and gave up 11 unanswered points. They went over six minutes without a basket in a Markelle Fultz-led 15-1 Magic run that turned a two-point edge into a cutting defeat.

By the end, the Nets shot just 33.3 percent, including 10 of 47 from deep as they missed 17 straight spanning the third and fourth quarters. They had the look of a car sputtering out of gas going uphill.

“Listen, [the starters] have been really good and this is just a stretch where I’d say that whole group is struggling a little bit right now,” coach Kenny Atkinson said. “So we’re going to need everybody to get out of this rut. I thought the bench stepped up, did a good job.

“Sure, I think there’s a little bit of crisis of confidence, there’s no doubt about it. … But that just happens during an NBA season. We’re just in a rut. We shot the ball real well early in the season, where we’re not shooting it well now. It’ll come back. I have confidence in these guys.”

Harris and Spencer Dinwiddie shared team-high honors with 16 points. But Harris had just three points in the second half, while Dinwiddie had a dozen in the third quarter when the Nets cut a 52-39 deficit to just four. They went ahead 78-76 on Wilson Chandler’s floater with 8:57 left to play.

But that’s when they forgot how to score. The Nets conceded the 15-1 run, including those 11 unanswered Orlando points.

“We’ve just got to get stops,” Dinwiddie said. “Obviously, we’re not making shots as a unit, so we have to rely on our defense.”

Fultz looked like Orlando’s reclamation project might be complete, with seven of his game-high 25 points in that game-deciding run, amid chants of MVP! MVP! Nikola Vucevic had 24 rebounds as the Magic battered the Nets 60-46 on the glass.

After Evan Fournier knotted it at 78-all, Fultz had a layup, a finger roll and a dagger 3 in succession. After his steal, Wes Iwundu’s free throws capped the run and left the Nets down 87-78.

Dinwiddie’s lone free throw finally broke the scoring drought at 3:55. But the Nets ended up missing a dozen straight shots — incredibly six of them layups — before Garrett Temple finally hit a 3-pointer. They’d gone 6:01 without a bucket, letting the game slip away.

Taurean Prince and Temple finished a combined 4-for-24. But Dinwiddie said the key is just to keep focused and not panic.

“We could very well just like last year go on a 7-0 run, and then everybody’s going to say we’re one of the best teams in the league,” Dinwiddie said.

“It’s just sticking to it, hammering away at the stone, and eventually, the stone breaks. It’s not going to be the first time you swing; it’s going to be one of the successive times.”