BOSTON – Ricky Davis scored nine of his 27 points in overtime, when the Boston Celtics went on a 9-0 run to beat the Knicks 114-100 in the season opener last night and spoil Larry Brown’s debut as Knicks coach.

Paul Pierce had 30 points and 12 rebounds, and Delonte West had 14 points, nine rebounds, and nine assists for the defending Atlantic Division champions. Stephon Marbury scored 22 and Eddy Curry had 19 points and eight rebounds in his first game since learning of a heart problem that led to his trade to New York.

Pierce had just four points in the second half, and just one in the fourth quarter. He missed one of two free throws with 16 seconds left in regulation and a chance to put the Boston up by three.

Instead, the Celtics led 94-92 and the Knicks sent it into overtime on Antonio Davis’s fade-away jumper with 2.6 seconds left in regulation.

But Pierce snapped out of it in overtime, and Ricky Davis also came on late for Boston.

After Marbury was called for an offensive foul, Pierce leaned into Matt Barnes to draw a shooting foul and made both free throws. Next time down, Pierce put a 3-point attempt from the left side over the rim, where Davis grabbed it and shot it back in for a 98-94 lead.

Marbury scored from the lane, then Mark Blount hit a pair of free throws to make it 100-96. Boston then scored the next nine points, starting when West went for a loose ball on the right side, choosing at the last minute not to let it go out of bounds off the Knicks.

He touch-passed to Davis in the corner, who sank a 3-pointer to make it 103-96 with 2:55 left.

The Celtics went 45-37 last season to win the most tightly contested – and most mediocre – division in the NBA. They were eliminated in the first round by the Indiana Pacers in seven games.

The Knicks tied for last in the division and missed the playoffs for the third time in four years. That’s when team President Isiah Thomas went after Brown, the former Detroit coach who signed a four-year deal worth at least $8 million a year.

Curry hadn’t played since March 28, two days before an irregular heartbeat put him on the Chicago Bulls’ bench for the last 13 games of the regular season and the playoffs. When one specialist suggested a DNA test to rule out a serious heart problem, Curry refused and he was traded to the Knicks.

The Knicks led by as many as six points in the first quarter and were ahead 39-31 midway through the second.

Quentin Richardson scored 11 points on 4-of-7 shooting in his first game as a Knick, and Jamal Crawford matched the effort with 11 of his own. New center Jerome James, signed as a free agent for $29 million in the off-season, had four points and four fouls in just eight minutes on the floor.