INDIANAPOLIS — The Celtics have steamrolled most of their opponents over the past month with their defense. It’s become their benchmark. They take pride in stopping teams.
That just wasn’t the case Sunday night at Gainbridge Fieldhouse, where the Celtics took a whipping from a new-look Indiana Pacers team headed for the NBA draft lottery. The Pacers spent the entire night hitting difficult shots, draining long 3-pointers, and picking apart the Celtics in the paint.
In one sequence, Oshae Brissett, who led the Pacers with a season-high 27 points, launched a 3-pointer and spun toward the crowd before the ball swished through the hoop, a la Steph Curry. He had a career-high six 3-pointers. Tyrese Haliburton launched a 39-footer to beat the shot clock. Swish.
Buddy Hield shot-putted a fadeaway 3-pointer with two defenders in his face. Bucket.
Boston really never stood a chance in the final eight minutes, as the Pacers bombarded the Celtics with baskets and pulled away for a 128-107 win.
The Celtics have won 11 of 13 games, with losses coming to the Eastern Conference bottom-feeding Pacers and Detroit Pistons. The setback snapped the Celtics’ road winning streak at seven games.
Coach Ime Udoka believes team defense has slipped since the All-Star Break, this time allowing Indiana’s shooters to get comfortable early, including Brissett, who hit three 3-pointers in a 68-second span of the second quarter.
“They made some easy shots early and then it snowballed,” Udoka said. “We did defend better [eventually], but credit to them, especially for the ones they hit late. But to start the game Haliburton, Hield, those guys were kind of walking into threes when we were under the 3-point line. You want to make them play inside the 3-point line.
“A guy like Brissett, he hit some tough ones. Looking at his numbers overall you can live with those, but the ones where their really good shooters like Haliburton, Hield, even [Malcolm] Brogdon, those looks are the ones where they hurt us.”
The Pacers (21-41), a middle-of-the-pack 3-point shooting team, made 17 treys, five above their season average. Brogdon, Haliburton and Hield combined for eight.
Meanwhile, the Celtics tried matching Indiana’s 3-point prowess but failed miserably, going 12 of 43. As shots missed, the Celtics players began putting their heads down and missing defensive assignments.
“They come out and they played amazing,” said the Celtics’ Jaylen Brown. “As a team, I thought they made a lot of tough baskets, tough shots. We have to be ready. Teams have been listening to what we have been doing over the past few weeks and we’ve got to be ready to take teams’ best shot.
“Indiana came out and I don’t think we stopped anybody. All of their guys, including Brissett, were like red hot from the field. Any time they did get an open shot, there was no question whether it was going in or not.”
Jayson Tatum scored 24 points but on 22 shots and missed 10 of his 12 3-point attempts. Brown added 23 but also picked up a technical foul and made several defensive mistakes.
The Pacers canned 12 threes in the first half and countered every Celtics rally with difficult shots. Brissett, scored a season-high 27 points, Haliburton, acquired last month from Sacramento, added 22 points and Hield scored 21. The Pacers shot 62.5 percent in a 35-point fourth quarter.
The Celtics grew frustrated in the third, with Brown picking up a technical foul for shoving Indiana center Goga Bitadze, a 7-foot, 250-pound mammoth, after the big man flattened him during a post-up. Brown had to be restrained from confronting Bitadze again, shoving away Robert Williams as he tried to intervene.
Brown said game officials admitted they missed the offensive foul call on Bitadze, causing even more disdain.
“They missed a call, it was pretty obvious,” Brown said. “That’s a big dude and I feel like he was trying to put something behind that [contact] trying to send a message. So that’s why I was upset, can’t miss a call like that. Officiating got me that tech.
“You can’t let a play like that go, that’s where my frustration was. You can’t miss that. That’s how stuff gets escalated. You can’t let someone get away with that.”
Despite their defensive slippage, the Celtics still hung close enough to steal a road win. Brown swished a 3-pointer to slice the deficit to 99-92 with 8:14 left. Those flickering hopes dissipated quickly when Hield drained a 3-pointer with two defenders in his face, and then scored seconds later after an Indiana steal. Pacers backup center Jalen Smith completed the game-deciding run with a 3-pointer for a 107-92 lead. The Celtics were done.
While Udoka credited the Pacers for making tough shots, he wasn’t pleased with the Celtics’ lackadaisical defensive approach, going under screens, not sprinting to close out to shooters, even on Haliburton’s shot from the Pacers’ logo. Udoka wanted better overall coverage on shooters.
“Some of those, you chalk up to tough shots, but I want our guys to be conscious of the shot clock, and if somebody is being guarded close, you know they are going to get it up, so take up some of that space,” he said. “It’s the NBA, guys are capable of making shots, so you don’t just back off because he’s at 35 feet. Some of these guys are shooters, and we let them get those shots, even late.
“I still think — you know, Brissett, 31 percent 3-point shooter, but we’re not closing out. He’s still a respectable shooter. We’re acting like he’s a cold guy. So some of those things weren’t our best tonight. Got to improve on those obviously.”
Gary Washburn is a Globe columnist. He can be reached at email@example.com. Follow him on Twitter @GwashburnGlobe.