BOSTON – For the first time this season, something is brewing for the Indiana Pacers. And for the first time in a long time, the Boston Celtics lost.

After the Eastern Conference Finals ended in one of the toughest victories in recent years, the Pacers appeared to be a team primed to take a step forward. Despite the loss, Rick Carlisle’s team showed it could maintain its constant offense in physical playoff basketball.

Then both franchises returned with essentially the same teams and saw drastically different results early on. The Celtics were still on top of the world while the Pacers sputtered out of the gate. But things are finally changing, and the Pacers’ 123-114 victory over the Celtics on Sunday showed that these teams are trending in opposite directions.

“We have to be a team of punchers,” Carlisle said. “We cannot be reactors. We have to be agitators. And tonight we were a lot more aggressive and that was the only way.”

Indiana has now won seven of its last 10 games, including a narrow loss to the West-leading Thunder and then a loss at Boston the next night. Other than those tough 24 hours, the Pacers have looked like themselves again.

The return of Andrew Nembhard has helped bolster the Pacers’ defensive line, which was frayed in early December. Indiana’s defense works when it has a reliable point defender who can pass the ball to Myles Turner without other players stepping in to help. Then the Pacers have plenty of length and speed around this primary defensive pairing to get the team into transition once they get the ball back. But in recent losses to the Thunder and Celtics, the Pacers simply took the ball out of the net far too often to maintain their lead.

That changed on Sunday when the main objective was to be the attacker.

Myles Turner with the putback SLAM 😳#NBAAllStar | https://t.co/T6jmxAY3iX pic.twitter.com/EyJna6pqzM

— Indiana Pacers (@Pacers) December 30, 2024

“It was playoff-like intensity,” Jaylen Brown said. “Give Indiana credit: They came out on top, you could see that. They tried to pressure us, tried to penetrate me, tried to enter my body, tried to turn me over. As a team you have to face this challenge every night.”

Ironically, Jayson Tatum said after the game that the Celtics had to be the team to strike first. The Celtics’ recipe for success last year was limitless versatility and strict adherence to principles. The Pacers are a laissez-faire vortex of movement and pace that needs to rely on a certain defensive intensity to actually work.

When Nembhard is out there, it’s easy for them.

“His impact is immeasurable,” Turner said. “He goes out and guards their best players and puts pressure on the rim. He hits hard and is someone who is very valuable to our team.”

Just as the Pacers are turning things around, the Celtics have lost their spark. Derrick White said this is the toughest stretch the team has faced since arriving in Boston. With the exception of Friday’s first game, a 142-105 win by the Celtics when the Pacers tied after a loss to the Thunder, they will be treated like the defending champs.

You already saw it last year when the entire league was made aware of it after Kristaps Porziņģis showed up for the first pre-season game. But it’s just different when the opposing coach can write “DEFENDING CHAMPS” on the board and underline it five times.

“Our guys just decided that whatever happens, it’s just as difficult a place to play and you’re playing against the NBA champions, the world champions,” Carlisle said. “We wanted to keep attacking and strike first as often as possible.”

The Celtics know they will see this most nights. A regular game for them is a statement game for everyone else. The losses were so rare last season that there wasn’t much stress to worry about. The biggest detriment to them getting into the playoffs was that they didn’t compete against each other enough Accident. But now they’re back in the kind of grind this team was all too familiar with before its championship run.

“I think we have the humility because we went through this,” Tatum said. “There were parts of the season where we took it for granted and I think we learned from that. But I think we’re just at a point in the season where we’re not happy with where we’re at, and we all need to understand that we played a part in where we are right now.”

Tatum said the Celtics need to get back to basics, that they need to communicate and make sure they don’t leave guys on an island. This was most evident when Tyrese Haliburton raced past Al Horford in crunch time for an easy layup.

The Celtics have had an unusually high number of defensive failures in recent weeks, regardless of the absences of Jrue Holiday and Porziņģis. The Celtics didn’t feel any real changes on the depth chart last year. Whoever was out there, it didn’t matter that much. They still put in a strong defensive performance and were able to keep their intensity high. At the moment it often seems to be one or the other.

“Every season has its own challenges, every season brings its own adversities and you have to face them,” Brown said. “You can’t believe that last year is this year or that this year will be last year.”

Brown loved the playoff intensity of this second Pacers game, but acknowledged there was some comfort on defense. White said it felt like they were running uphill, so they had to play with joy again.

“It will help us grow if we look at it with the right intent and the right perspective,” Brown said. “We can’t complain about it, otherwise we’ll just have to rise to the challenge and I feel like we’ll do better.”

As New York and Orlando close in the standings, the Celtics are about to embark on an exciting road trip through Minnesota, Houston, Oklahoma City and Denver. These are teams that will test their defensive physicality and acumen.

“All the guys that are in this locker room, those are the guys that I want to go to war with,” White said. “I’m confident about that.”

Now that the Pacers have Nembhard back, their identity is starting to emerge again. At the crucial time, they kept running. They didn’t want to run for time, which Haliburton acknowledged was contradictory. But that’s exactly what they are.

“I think we set a precedent for how we want to play,” Turner said. “I think that’s our advantage because we get into the fourth quarter and we start competing against teams that don’t really want to compete with us.”

Carlisle praised sophomore forward Jarace Walker for playing until exhaustion. It’s a rite of passage on the team that gets everyone else at their best. The Pacers are finally going back to the team you don’t want to play against. The Celtics appear to be more vulnerable than they have been in over a year. This is just another wave in the NBA season, but both teams still have work to do to get back to where they expected.

(Photo of Indiana’s Myles Turner dunking on Boston’s Jaylen Brown: Bob DeChiara/Imagn Images)