CHICAGO — The Nets played the worst half in their history Friday night, en route to one of their worst beatings in years.

Coming out of the All-Star break, they played as if their minds were still on vacation and took a wire-to-wire thrashing by the Bulls, 131-87, before a sellout crowd of 21,286 at United Center.

It was a rout of historic proportions.

The Nets trailed by as many as 50, and were behind 63-29 at the break. They shot 24.4 percent overall in the first half and just 13.6 from behind the 3-point arc.

It was the first time since April 26, 2012 against Toronto — before the move to Brooklyn, back when they were the New Jersey Nets — that they had been held under 30 points in a first half, according to YES Network. It matched the lowest output by any NBA team in a half this season, and was the first time any team had been held under 30 in a first half since the Clippers on Jan. 11, 2022, per Elias Sports Bureau.

Yes, the game was every bit that one-sided. And the Nets (34-25) were every bit that bad.

Cam Thomas led the Nets — who have not scored more than 116 points in a game since trading away Kevin Durant and Kyrie Irving — with 22 points off the bench. Seth Curry added 19.

But Friday they got just 34 points from the starting lineup (two more than the 32 Chicago’s Zach LaVine scored by himself) and shot just 12-for-44 from 3-point range. The Nets have to find some scoring.

The Nets — 3-5 since Irving’s trade demand derailed their title hopes — had their lead on the Knicks for the sixth seed in the Eastern Conference cut to a single game. The two teams will play at the Garden on Wednesday.

If they keep playing like this, the Nets could be looking up at their cross-river rivals by then, not down.

The Nets coughed up the first 11 points of the night, and trailed by 50 multiple times in the fourth quarter.

But unlike their 43-point loss in Boston on Feb. 1 — after which Irving talked about finding a way to beat the Celtics, then proceeded to force a trade to Dallas — this one didn’t come against a potential NBA champion. This humiliation came against a struggling Bulls squad that had lost six straight coming in.

The Nets spit the bit right from the start. Five straight misses to open the game and three quick turnovers spotted Chicago an 11-0 lead.

The deficit swelled to 48-22 with 5:25 left in the second quarter as the Nets shot just 8-for-32 from the floor and 2-for-18 from 3-point range.

It only got worse from there.

Bulls center Andre Drummond threw down an alley-oop against his former team, leaving the Nets in a 101-51 hole with 11:04 to play.

Coby White’s driving, floating bank shot made it 103-53 with 9:42 to play.

The Nets narrowly avoided having the lowest scoring output by any team this season; the Cavaliers were held to 81 by the Knicks. But that will be precious little solace to a team clearly listing and in desperate need of some offensive punch.