On Friday night, the Celtics coughed up a 17-point second-half lead and lost to the Cavaliers. On Sunday afternoon, there was some uneasiness inside TD Garden as a similar scene began to unfold.

The Nuggets wiped away most of a 20-point deficit. But this time, the Celtics were able to steady themselves before it was too late. After Denver pulled within 3 in the final quarter, Derrick White and Al Horford gave the Celtics the finishing kick they needed to secure a 110-103 win and snap a two-game losing streak.

Jaylen Brown had 22 points to lead the Celtics, and Horford tallied 19 points and 8 rebounds. Jamal Murray scored 26 points to lead Denver. The Celtics remained without Jrue Holiday (finger) and Kristaps Porzingis (illness), and Aaron Gordon (ankle) was sidelined for Denver.

The Celtics led, 68-48, early in the third quarter. But Murray scored inside with 8:58 left to pull the Nuggets within 88-84. On Friday, the Celtics leaned heavily on their stars to carry them. But the backups were essential on Sunday. In this case, Boston answered with a layup by Neemias Queta, a jumper by Sam Hauser, and a layup by Payton Pritchard, a 6-0 burst crafted by the reserves that stretched the lead back to double digits.

The Nuggets lingered, slicing the deficit to 4 for the third time in the period on a 3-pointer by Nikola Jokic that made it 95-91 with 5:56 left.

Tatum, who scored 46 points Friday, struggled Sunday. His sixth turnover followed by a missed 3-pointer opened the door for Denver, and a Murray layup with 1:16 left made it 102-99. The Celtics hunted defensive matchups against Murray all day, but his block on Brown inside on the ensuing possession gave Denver a chance. But White streaked in, scooped up the loose ball and hit a floater to give Boston some breathing room.

A Murray turnover then led to a fast-break layup by Horford, helping the Celtics escape.

On the game’s first possession Russell Westbrook hit a 3-pointer, and that was probably a favorable result for the Celtics, because it empowered the mercurial shooter to fire away. Westbrook missed his four other 3-point attempts in the first half.

Horford was a central part of Boston’s offense, primarily with post-ups, and his 3-pointer from the top of the key with 3:41 left capped an 8-0 run that gave the Celtics a 23-13 lead.

Coach Joe Mazzulla essentially used seven players in Friday’s loss to the Cavaliers but he extended his rotation a bit on Sunday, and the backups were productive in the first half. Pritchard, Hauser and Queta combined to go 7 for 8 from the field, with Pritchard and Hauser drilling 5 of 6 3-pointers.

Hauser’s second 3-pointer of the half gave the Celtics a 47-29 lead, and Boston eventually extended its advantage to 59-39 before a 9-0 Nuggets burst helped them pull within 61-48 at the break.

Boston scored the first seven points of the third quarter to push its lead to 20, but it was unable to put away this pesky Denver team. The Nuggets responded with a 9-0 burst that was capped by a Braun dunk that followed a Tatum turnover.

And with Boston leading, 80-64, and just over four minutes left, the Nuggets closed the quarter with a 13-3 surge that was capped by consecutive Murray baskets to pull within six at the start of the fourth.

Adam Himmelsbach can be reached at [email protected]. Follow him @adamhimmelsbach.