Jaylen Brown celebrated his 21st birthday by playing one of the best games of his young career.

Brown scored 23 points — just two points shy of the career high he set in last week’s season-opener — and the Boston Celtics beat the New York Knicks 110-89 on Tuesday night. He left the court with the perfect present — a win.

“You can’t beat that,” he said.

Rookie Jayson Tatum added 22 points. Kyrie Irving finished with 20 points and seven assists. Al Horford chipped in with 13 points and 13 rebounds.

After dropping their first two games to open the season, the Celtics have won two straight. The Knicks remain winless through their first three games.

Brown and Tatum were both taken No. 3 overall by the Celtics in the last two drafts, and became fast friends because of their proximity in age.

Brown was active from the opening tip, connecting on 5 of his first 8 shots and scoring 13 points in the first quarter. He said he has been the beneficiary of teams paying so much attention to Irving and Horford.

“They draw a lot of attention, so I’ve got to make plays when they’re taking up a lot of that attention,” Brown said. “Me and Jayson, we’ve got to make teams guard us.”

Enes Kanter led New York with 16 points and 19 rebounds. But he got most of them in a first half in as his team struggled mightily from the field. The Knicks scored the first basket of the night, but never led again. They shot just 42 percent and went 1 of 12 from the 3- point line.

Kanter had 16 rebounds in the first half for the Knicks. New York went 0 for 6 from 3-point line and committed 11 turnovers in the first half.

Boston played without guard Marcus Smart, who sat out his second straight game with a sprained left ankle.

But they didn’t need him. The Celtics played like a team coming off four days’ rest, taking as much as a 25- point lead late in the second quarter.

New York never recovered.

Knicks coach Jeff Hornacek said before the game that Tim Hardaway Jr. had been playing through a preseason ankle injury. He took a couple of hard spills, but still logged 28 minutes. He finished with six points, connecting on just 2 of his 11 shots.

Next — The Celtics begin a two-game road trip Thursday at Milwaukee.