The Knicks' Jalen Brunson is defended by the Indiana Pacers' Quenton...

The Knicks' Jalen Brunson is defended by the Indiana Pacers' Quenton Jackson during the second half of an NBA game on Sunday in Indianapolis. Credit: AP/Darron Cummings

INDIANAPOLIS — Even with a one-sided win over Indiana at Madison Square Garden in their home opener this season, a trip to Gainbridge Fieldhouse is hardly a welcoming sight for the Knicks. They’d lost all four games here last season, including all three in the Eastern Conference semifinals.

And against a shorthanded Indiana squad on Sunday, the Knicks found themselves struggling again. Just like last spring, they had to watch Tyrese Haliburton celebrating as they slumped their shoulders and searched for answers while heading to a late timeout.

But the common denominator this time wasn’t as much the location as the recent struggles. They had defensive lapses as they watched a fourth-quarter lead disappear down the stretch for the third time in the last four games.

This time a 10-point lead in the third quarter and a two-point edge early in the fourth quarter were wiped out as they fell apart in a 132-121 loss to the Pacers.

After allowing 34 points in the third quarter, the Knicks saw the Pacers pile up 40 points in the fourth to pull away. Indiana shot 14-for-22 in the fourth quarter, including 8-for-13 from beyond the arc.

“I mean, same things you guys saw,” Jalen Brunson said. “We just weren’t together. I had a couple of plays in the first half where I just fell asleep. And it doesn’t look like a big thing then, but when you look at all the little mistakes, it adds up to what could have been a closer game and what could have been a win for us. We’ve just got to stick together on that side of the ball regardless of what’s going on.”

“They’re a great offensive team,” coach Tom Thibodeau said. “And we gave up way too much. We don’t challenge shots, they’re going to make. So too big of a discrepancy from the three-point line. They made 21, we made seven. That’s a problem.

“Our offense, we score 121, we shoot 55%. Get to the line a lot. Outrebounded them. But didn’t cover the line. So we got to fix it and we got to fix it fast.”

Indiana shot 21-for-46 from beyond the arc and the Knicks were 7-for-25.

Brunson had 33 points, Karl-Anthony Towns added 30 and OG Anunoby had 25 for the Knicks (4-5). Mikal Bridges had only eight, ending a string of seven straight games in which all five starters finished in double figures.

Bennedict Mathurin shot 7-for-9 from behind the arc and scored 38 points for Indiana (5-5). Haliburton had 35 points and 14 assists after being held scoreless and shooting 0-for-8 in the Pacers’ earlier game against the Knicks. Myles Turner was 5-for-8 from three-point range and added 26 points.

The three-pointers were back-breakers all night. The Knicks trailed 108-105 after Anunoby’s dunk with 5:43 left, but back-to-back three-pointers by Turner sandwiched around Brunson’s jumper stretched Indiana’s lead to 114-107 with 4:50 remaining.

“They hit threes,” Towns said. “They did what they had to do. Credit to them. They hit shots when they had to hit shots. We just didn’t do enough to win tonight.

“We’ve gotta be better with transition defense. I think that allowed them the threes that got them going, that got them confident in the three-ball. Early on especially, transition threes.

“I thought we did a good job playing defense when we got them in a halfcourt set, making them take some tough ones or the shots that we wanted. The transition got them going, and then later on in the game, it hurt us again when we needed to get some stops.”

Said Josh Hart: “We’ve just got to work on getting them out of their sets, getting them out of rhythm better. Especially with this team. If you have one breakdown, they find it and they get in the lane, they drive, kick and they’ve got shooters all over the place. We’ve got to communicate better.

“We’ll figure it out. Not even 10 games in. We’re not worried. We’re going to figure it out, and when we figure it out, offensively we’ve been great.”

Notes & quotes: Thibodeau would not speculate on the possibility of Cam Payne returning in Philadelphia on Tuesday night but said he’s closer than Precious Achiuwa, who has not been cleared for practice despite doing some work on the court.