Tatum had just given the Celtics a three-point lead with two free throws with 7.9 seconds left and the Knicks called their final timeout. They had trouble getting the ball inbounded from the sideline, and Knicks guard Trey Burke had to race into the backcourt to retrieve it as the clocked ran down. He pulled up for a 3-pointer from well beyond the arc and Tatum jumped to contest it, fouling Burke for three free throws that could have tied it.

But he missed the first and the Knicks couldn’t grab the rebound when he intentionally missed the third.

Kyrie Irving and Marcus Morris each added 16 points for the Celtics, who rebounded from their loss in Toronto on Friday night. They won despite giving Gordon Hayward a night off to rest his surgically repaired left ankle.

Tim Hardaway Jr. scored 24 points for the Knicks, who lost rookie Kevin Knox to a sprained left ankle in the first quarter. Enes Kanter had 17 points and 15 rebounds before fouling out of their second two-point loss in two nights.

The Celtics are considered one of the Eastern Conference favorites but coach Brad Stevens said the Raptors were clearly better now and Boston needed to improve after Toronto’s 113-101 victory Friday night.

On Saturday night, they were just good enough to beat the rebuilding Knicks.

The Celtics looked sharp early in racing to a 26-10 lead Saturday and still had a double-digit cushion midway through the second quarter before Damyean Dotson’s second straight 3-pointer trimmed it to 50-48 by halftime.

Boston seemed to be regaining control early in the fourth quarter but again the Knicks came back, tying it at 89 on consecutive 3-pointers by Hardaway. But Irving had five points and an assist in a 7-0 burst that put the Celtics on top again and they held on from there, with Tatum hitting a tough turnaround jumper with 21 seconds left and missing a dunk earlier in the possession.

TIP-INS

Celtics: Aron Baynes got the start with Hayward out and scored 10 points. But he played only 12 minutes before leaving with a sore right hamstring. … Jaylen Brown was only 2 for 9, finishing with seven points.

Knicks: Coach David Fizdale said G Courtney Lee would see specialists Monday after experiencing neck spasms that went down into his chest. Lee was sidelined throughout the preseason by a neck injury. … Kanter became the first Knick since Zach Randolph (2007-08) to start the season with three straight double-doubles.

KNOX KNOCKED OUT

Knox was driving for a layup on a fast break when his ankle appeared to roll badly as he was fouled by Terry Rozier III. Knox stayed on the court briefly, appearing in pain, then was carried off by a pair of teammates.

Because the No. 9 pick wasn’t able to shoot the free throws, he was, by rule, forced to miss the remainder of the game. The Knicks said X-rays on his ankle were negative.

HAYWARD’S HEALTH

Celtics coach Brad Stevens said there wasn’t a plan to rest Hayward on back-to-backs, but his minutes are being watched and he’s being evaluated on a game-by-game basis. He said Hayward, who broke his ankle last year in the season opener, was just experiencing general soreness Saturday and didn’t think it was anything overly concerning.

UP NEXT

Celtics: Host Orlando on Monday night.

Knicks: Visit Milwaukee on Monday night.