BOSTON — The Celtics set a season-worst three-game losing streak on Sunday against a team that entered the day tied for the worst record in the NBA.

It doesn't get much worse than that for a squad that began the week having lost only 10 games all season.

Boston was able to cut a 19-point deficit through three quarters down to seven with less than two minutes to play. But 10 minutes of solid defense could not make up for three quarters of sleepwalking as Boston lost, 103-95, to an Orlando Magic team that started the day with only 13 wins this year.

“We’ve got to hit some adversity,” rationalized Celtics All-Star Kyrie Irving of a team that still remains atop the Eastern Conference with a 34-13 record. “We’ve got to hit something. We need it as a team. There's a lot more adversity down the road. We’ve got to be able to weather the storm no matter what.

“Whether you’re playing extremely well — and that may result in a loss — or whether you are not necessarily making the amount of shots you would like, or doing things at the optimal level you would like — that’s part of the game, and learning one another, and figuring out how you’re going to respond from that.”

Irving scored 40 points on 14-of-23 shooting, with five 3-pointers, in his return from missing a game with a sore left shoulder. But he got little help from his friends on either end of the court. While Jaylen Brown had 17 points on 7-of-12 shooting, the Celtics shot 43.5 percent overall and only 8-of-27 (29.5 percent) on 3-pointers.

Elfrid Payton scored 22 points for the Magic, who went cold in the fourth quarter, but were able to hold the Celtics off with hustle plays on loose balls and offensive rebounds.

“I felt like we could never catch up — especially with momentum plays,” said Al Horford, who scored just nine points on 4-of-11 shooting. “We had fast-break situations that we weren’t converting. Then that was killing us because then they were coming back the other way. A lot of plays we could capitalize on; we just weren’t able to do that.”

The Celtics were up one at the half before the Magic outscored Boston, 32-12, in a third quarter in which the Celtics committed eight turnovers. The Celtics held Orlando to just 13 points on 5-of-25 shooting in the fourth. But by then the damage was largely done.

“In the third quarter our offense was poor,” Celtics coach Brad Stevens said. “But today was not about the offensive side. It felt like they were shooting layups for the most part — even the ones they missed late. ... We haven’t played well consistently on both ends for a while now.”

Down 19 entering the fourth quarter, the Celtics held the Magic without a point for the first 2:36 of the final session, but could manage only four themselves with Irving’s jumper cutting the gap to 90-75.

Baskets from Jayson Tatum and Brown had it 93-79 with 7:37 on the clock before Tatum’s put-back brought the Celtics within 12 with 7:07 to go. A Tatum 3-pointer made it a nine-point difference, and the Celtics had three chances to make it a two-possession game, before Payton got to the line for a 94-84 game with 4:34 to play.

Irving was fouled on a 3-point shot and hit two of three to knock the gap to eight with 4:16 left. Payton answered with a jumper and Khem Birch had an easy put-back for a 12-point game before Horford’s 3-pointer brought the Celtics within 98-89 with 2:51 remaining.

Irving scored in the lane for a seven-point gap with 1:44 to go. Boston forced a miss, but again Birch was there for a put-back. A Horford basket from Irving made it 100-93 before the Celtics intentionally fouled Payton and he hit one of two with 1:01 to play.

The Celtics were then held to just two Irving free throws with 36.2 seconds to go the rest of the way.

“They were really good being active around the rim,” Stevens said of the Magic, “and got their hands on a lot of balls, came up with a lot, until that fourth-quarter spurt. Then we got a bunch of stops in a row and we missed a bunch of transition opportunities and layups in a row.”