Kevin Garnett had 26 points and 10 rebounds, Rajon Rondo added 21 points and 12 assists, and the Celtics swept their way into the Eastern Conference semifinals, holding on for a 101-89 win over the Knicks on Sunday.
Ray Allen and reserve Glen Davis each added 14 points for the Celtics, the first team into the second round after sweeping a series for the first time since a 3-0 victory over Indiana in 1992, the last series victory for their old Big Three before Larry Bird retired.
They had a 23-point lead cut to four in the fourth quarter, but pulled away again behind Garnett, who scored 20 after halftime.
The current Big Three of Garnett, Allen and Paul Pierce twice was extended to seven games in the first round, but this one was far easier than expected against the injury-weakened Knicks. The Celtics could now have a week off while they wait for likely second-round opponent Miami, which was forced to a fifth game earlier Sunday after a late rally by Philadelphia.
"We know we have played very well when we've had rest and preparation time. So those are always good," Celtics coach Doc Rivers said.
Carmelo Anthony had 32 points and nine rebounds, and Amare Stoudemire, who decided to play after his back felt better, finished with 19 points and 12 boards but shot only 5 of 20 from the field.
"It was all heart. He just gave it all. With him and Carmelo going forward, the Knicks are in good shape," Knicks coach Mike D'Antoni said.
The Knicks shot 34 percent and were quickly dispatched in their first playoff appearance since 2004, when they were also swept in the first round. They haven't won a playoff game in 10 years.
The Celtics were only 10-11 in their last 21 games of the regular season, struggling to adjust to a changed lineup after trading center Kendrick Perkins to Oklahoma City at the deadline and renewing questions they were too old. The Knicks believed they could challenge them, but Chauncey Billups was lost for good after straining his left knee in the final minute of Game 1 and Stoudemire was never the same after hurting his back during warmups before Game 2.
Garnett made three consecutive field goals to make it 70-48 in the third quarter before the Celtics let the Knicks back into it. Consecutive run-out dunks by Anthony cut it to 14, and New York had it all the way down to 10 when Shawne Williams' 3-pointer with 36 seconds remaining trimmed it to 82-72 after three.
Stoudemire opened the fourth with a basket and Anthony followed, bringing it within six and forcing Rivers to put Garnett back into the game. He made a pair of free throws, but baskets by Stoudemire and Anthony Carter made it 84-80 with 7:34 to go.
"I thought we dropped the guard a little bit," Rivers said. "Give them credit, I thought they played desperate and you could see it in their play and their defensive energy."
But Boston would never let it get closer.