BOSTON – Before the Cleveland Cavaliers put their perfect 15-0 start to the season to the test Tuesday night at TD Garden against the defending NBA champion Celtics, Cavaliers coach Kenny Atkinson was asked what he hoped to get out of the game.

“We want feedback,” Atkinson said. “More feedback. Hopefully we’ll see this team in a big game later. On the other hand, I don’t want to blow this game out of proportion. It’s that balance, but it’s more about seeing where we are. And we all know that our schedule hasn’t been the hardest.

“We’re playing against an elite team, the top team in the league. So I can’t wait to get some feedback on the match.”

Over the next 48 minutes, Atkinson got his wish. The result? Boston, despite a great charge from Cleveland after halftime, had enough to hold off the Cavaliers 120-117, ending Cleveland’s impeccable start.

The loss left the Cavaliers tied for the second-longest single-season winning streak in NBA history — though Cleveland undoubtedly deserved some respect for that.

However, respect does not always translate into victories. And after spending nearly a month with a zero in the loss column, Cleveland now has a number there thanks to a 33-point, 12-rebound, 7-assist effort from Jayson Tatum, one of six Celtics to score in double figures.

Boston came out red hot from beyond the three-point arc, going 22-for-41 from deep, while the Celtics — who led by as many as 21 — held off a second-half charge from Cleveland as the Cavaliers pounded. away in the paint.

When these teams meet again in the playoffs next spring — as they did last season in the Eastern Conference semifinals — the game will likely be a split along the same lines as Tuesday, with the Celtics trying to dominate the three-point line and the Cavaliers are trying to do the same in the paint.

In this one, both teams got what they wanted. Boston shot 14-for-22 from deep in the first half — the Celtics’ best three-point shooting in 25 years, with at least 20 attempts. However, the Celtics shot 22-for-45 from beyond the arc, while Cleveland went 36-for-64 from 2, including a 60-36 edge in points in the paint.

It was a parade of forays to the edge of Cleveland especially in the third quarter, allowing Atkinson’s team to get back into the game as the Cavaliers scored 22 points in the paint in the quarter alone – as many as Boston. in the game up to that point.

By then, the party atmosphere at TD Garden gave way early to a bitterly competitive atmosphere – complete with the crowd cheering with applause and dismay in a way that would have felt at home had this been a continuation of last year’s playoff series spring. That included the physicality with which both teams played, and the lack of fouls called regardless.

But in the end, Boston had enough to hold off Cleveland’s comeback, with a key Payton Pritchard 3-pointer with 5:31 left giving Boston a 107-100 lead, creating enough separation to ensure Cleveland’s perfect start came to an end.

For his part, Celtics coach Joe Mazzulla said he saw this game as an opportunity for his Celtics (12-3) to strengthen specific things that have been bothering them lately: individual defense and positioning, and rebounding in general.

How did that go? Boston won the rebounding battle 42-41, despite playing the combination of Evan Mobley (22 points, 11 rebounds, 6 assists) and Jarrett Allen (10 points, 11 rebounds), and with Kristaps Porzingis still recovering from a operation out of season.

Boston’s individual defense, meanwhile, had a huge impact on Darius Garland, who had just eight points on 3-for-21 shooting.