NBA

O’Neal, late miscues cause Nets’ downfall

TOUGH SLEDDING: Kris Humphries plays tight defense on Paul Pierce during the Nets’ 89-83 loss to the Celtics last night in Boston. (Getty Images)

BOSTON — With all due respects to Pogo and Walt Kelly, the Nets met the enemy last night and it was them. Again.

“We’re 5-10 but I don’t think we’re a 5-10 team,” Avery Johnson said. “Realistically, maybe 8-7. I don’t think we’re five games below .500.”

But that’s what the standings say and last night, an 89-83 loss to the defending Eastern Champ but point guard-light Celtics here, was one of those games that lends support. They played a terrific first half, led by eight. Then . . .

“We let their defense control determine out offensive execution,” said Anthony Morrow (18 points).

“We had a stretch where we were turning the ball over, giving them chances in transition and we had some defensive malfunctions late in the game,” said Devin Harris (20 points).

Before those defensive malfunctions there were offensive flubs, gaffes and whatever else you want to call them. And nine of them, also called turnovers, came in the third quarter.

“Just getting a shot up against a pass that’s 50-50 on getting turned over would have been so much better,” said Kris Humphries (two points, 11 rebounds).

“We just got careless with the ball. We had stops but couldn’t get anything going,” Brook Lopez (16 points) claimed.

So scoring just 37 points in a turnover-ravaged second half, the Nets failed to take advantage of the early struggles by the Celtics. And giving the Celtics additional chances is like repeatedly checking for a gas leak with a match. Eventually there’s a loud noise.

And the Celtics finally went boom in the fourth quarter. Sustained all night by Shaquille O’Neal’s 25-point, 11-rebound brute inside force, the Celtics rode the endgame shooting of Paul Pierce (18 points) and Ray Allen (15 points) while holding off a final Nets rally.

The Nets, playing from ahead most of the game but undoing much of it with 18 turnovers, surrendered the lead for good to a 3-pointer by Allen at 8:07.

After O’Neal added a pair of free throws for a 72-67 lead, the closest the Nets would get again was one point on a Harris floater at 5:09. The key Boston explosion followed in a span of 2:06 on three scores by Pierce and another triple by Allen. And as Johnson allowed, the Celtics were noisy defensively, too.

“They raised the volume up on their defense and we just didn’t do a good job in the third quarter especially offensively,” the coach said.

The Celtics received a disheartening jolt late in the first half. Already without Rajon Rondo, who missed his third game with a hamstring injury, the Celtics lost Delonte West to a broken right wrist. West took an awkward fall after scoring on a fastbreak layup at 2:43.

Boston’s point situation became even more precarious in the third quarter when Nate Robinson sustained his fourth foul just 40 seconds into the second half. Marquis Daniels got the job by default.

And as the Celtics muddled through their problem, the Nets were simply muddling. And stumbling. And passing to the wrong team. After working so hard and so well to claim an almost stunning 8-point halftime lead, the Nets let loose the Keystone Kops collection of turnovers.

Six of them came before 3:30 had transpired and what saved the Nets early was that the Celtics only converted after two of them. The Nets, Lopez doing the honors, scored first in the third quarter to go up 10 and then a dizzying display of traveling, passing to Celtics and dropping teammate passes ensued.

fred.kerber@nypost.com