Marcus Morris scored 22 points for Boston, and Gordon Hayward had 14 off the bench.

Mike Conley led Memphis with 26 points, while Dillon Brooks added 19. Jaren Jackson Jr and Marc Gasol finished with 15 points apiece.

Irving scored 22 in the second half for the Celtics, who trailed by 19 early in the second half but force the Grizzlies into 1-for-16 shooting to start the fourth. A pair of layups by Irving erased the Memphis lead at the midway point of the period.

The teams exchanged the lead five times in the quarter before baskets from Morris and Hayward gave Boston a slight edge. Horford’s 3-pointer with 1:32 left gave Boston a 103-99 lead and another one with 34 seconds left — his fifth of the night — ended Memphis’ hopes.

Memphis played a solid first half to carry a 64-47 lead at the break. The Grizzlies shot 65 percent for the half, despite going 4 of 13 from outside the arc.

Conley had 12 and Gasol and Jackson added 11 apiece for Memphis.

Meanwhile, Boston was at 45 percent. No Celtics had reached double figures, and Irving, who entered the game averaging 23.3 points, was stymied at four points on one field goal and a pair of free throws.

Irving would become much more a part of the Boston offense in the third quarter, scoring 12 points. That helped Boston whittle away at what was once a 19-point lead just after halftime. Memphis committed eight turnovers in the period and its lead was down to 87-79 after three.

TIP-INS

Celtics: Rookie F Robert Williams missed his second straight game with a left groin strain. … Boston has won last four in the series. … Horford’s five 3-pointers matched his career high set against Houston on Dec. 29, 2015.

Grizzlies: Gasol has made a 3-pointer in 12 straight games, one short of his career-best 13 in December 2017. … Brooks was 4 of 5 from outside the arc. … Gasol had 10 assists.

UP NEXT

Celtics: Visit San Antonio on Monday.

Grizzlies: Visit Houston on Monday.