Brandon Ingram highlighted a 33-point performance by hitting a go-ahead 3-pointer with 33.3 seconds left in overtime, and the New Orleans Pelicans held on for 120-115 victory over the Boston Celtics on Sunday after rallying from 24 points down in the third quarter.

Zion Williamson scored 24 of his 28 points after halftime and had 10 rebounds, four assists and a block for the Pelicans, who narrowly avoided losing for the sixth time in seven games. Josh Hart, who was instrumental in the comeback, had 17 points, 10 rebounds, three blocks and a steal.

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Jayson Tatum had 32 points and nine rebounds, and Jaylen Brown scored 25 for the Celtics, who appeared to be cruising to their third victory in four games when Tristan Thompson's free throws gave Boston a 79-55 lead in the middle of the third quarter.

The Pelicans finished the period on a 19-8 run, capped by Williamson's layup after he drove nearly the length of the court to score with less than 2 seconds on the clock.

The momentum carried into the fourth.

Williamson's put-back dunk ignited a 10-2 run during which Hart scored 8 in a spurt that included his driving layup as he was fouled, a 3 and a reverse put-back after Lonzo Ball's fast-break layup had been blocked by Daniel Theis.

New Orleans pulled even when Ingram's transition 3 made it 98-all with 4:10 left, setting up a riveting finish to what had looked like a laugher.

The lead changed hands twice in the last 11 seconds of regulation, with Tatum draining a fall-away to make it 106-105 and Williamson hitting a layup as he was fouled to put the Pelicans up 108-106 with 6.9 seconds to go. Tatum then sank a driving floater in the final second to force overtime.

The game was tied at 112 when Ingram's 3 put the Pelicans in front to stay.

The Celtics controlled most of the first half, scoring 19 points off of 10 first-half New Orleans turnovers, while the Pelicans didn't convert any of Boston's three turnovers into points in the opening 24 minutes.

Tatum exploded for 17 points in the second quarter, when Boston led by as many as 19 before taking a 63-47 lead into halftime.

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TIP-INS

Celtics: Coach Brad Stevens said Marcus Smart, who has not played since injuring his calf during a Jan. 30 loss to the Lakers, is traveling with the team. But while Stevens said Smart has been "going at a decent rate the last few days," he stressed that it remains uncertain when Smart will be ready to return to the lineup. ... Boston fell to 14-5 when leading at halftime. ... Thompson and Kemba Walker each scored 14 points and Aaron Nesmith scored 10. ... Robert Williams III grabbed 143 rebounds, blocked four shots and scored eight points. ... Boston shot 39.8% (39 of 98), including 10 of 27 from 3-point range.

Pelicans: Ball scored 16 points and Willy Hernangomez grabbed 13 rebounds. ... JJ Redick was ejected after committing a pair of technical fouls within the first minute of the fourth quarter. His first technical came while arguing, the second after he hastily bounce-passed the ball to an official after Boston's Nesmith was called for fouling him on a drive. ... New Orleans missed six straight free throws in the third quarter and finished 25 of 37 for the game from the foul line. ... The Pelicans shot 44.7% (42 of 94), including 11 of 36 from deep.

UP NEXT

Celtics: Visit Dallas on Tuesday night in the second game of a three-game trip that ends in Atlanta.

Pelicans: Host Detroit on Wednesday night before starting a two-game road trip.