Carmelo Anthony did everything any one player can do to will his team to victory.
The New York Knicks still came up short.
The Celtics survived his virtuoso performance, 96-93.
"We were lucky to win," coach Doc Rivers said after the game.
Kevin Garnett sank the go-ahead basket with 14 seconds left then stole the ball with 4 seconds remaining as the Knicks gave the Celtics all they could handle in falling into an 0-2 hole in the series.
"I probably (have) never been more proud of a team and how they battled the circumstances," Knicks coach Mike D'Antoni said, "how hard they played and how tough they played."
Billups had a strained left knee and his status for Game 3 on Friday night at Madison Square Garden is uncertain. Stoudemire had back spasms but expects to be back when the best-of-seven series resumes.
Rajon Rondo led the Celtics with a career playoff-high 30 points, 14 of them in the first quarter when he kept driving to the basket.
"I tried to attack Game 1," he said, "It's just (that) my lanes were getting blocked."
Anthony matched his career playoff high for points and set a new high with 17 rebounds as the Knicks held a 53-37 advantage on the boards. Toney Douglas had 14 points in place of Billups.
Now the sixth-seeded Knicks, who have tested the third-seeded Celtics, must win at least one of two at home to bring the series back to Boston.
"The Celtics didn't do anything special," Anthony said. "They won two games on their home court. Now it's our turn to go to our home court and try to do the same thing."
Rivers wasn't raving about his team's play, either.
"We didn't execute very well," he said. "We played hard. ... Hard is great. Hard and smart is much better."
Garnett hit the decisive jump hook after backing Jared Jeffries into the lane.
"I wasn't really in a nice rhythm," said Garnett, who had 12 points and 10 rebounds. "I just remained calm, went to a shot I knew I could make."
Anthony was the obvious choice to shoot on New York's final possession. So Pierce and Glen Davis swarmed him when he got the ball just inches from Boston's bench, forcing him to pass to Jeffries, who tried an interior pass instead of going up with the shot.
D'Antoni said Anthony made the right play.
"He's the best at closing the game," D'Antoni said.
In the opener, though, Anthony missed a long 3-point attempt with 2 seconds left.
Garnett said he was simply reacting when he made the steal, as Jeffries hesitated momentarily.
"When I caught it my initial route was there, but I felt like KG was coming and closing down," Jeffries said. "I should have went ahead and shot the ball."
The Knicks then fouled Delonte West, who made two free throws with 0.6 seconds to go.
The Knicks had gone ahead 91-88 with 2:35 left when Anthony took a pass beyond the left arc and made a 3-pointer despite being bumped by Pierce. Pierce followed with two free throws, then both teams missed jumpers.
On the next possession, Pierce drove the lane to draw a defender and fed a wide-open Garnett for a dunk that put the Celtics on top 92-91 with 49 seconds to go.
Jeffries followed with a layup, giving New York its last lead at 93-92 with 20 seconds left.
With the score tied at 59, the Celtics went on a 15-4 run led by Pierce's seven points. Allen and Jeff Green hit 3-pointers during the surge that put Boston on top 74-63 with 45 seconds left in the third quarter.
Then Anthony single-handedly brought the Knicks back by scoring their first seven points of the fourth quarter, while Boston managed only a jumper by Pierce. New York was making a game of it, down only 76-74 with 10:01 to play. At that point, Anthony had scored the Knicks' previous 13 points and 18 of 20.
After a timeout, Ronny Turiaf tied the game for the Knicks at 76 with a short jumper.
Rondo, threading his way at high speed through New York's big men, had 14 of Boston's first 18 points after scoring just 10 in Game 1. He went to the bench for a rest of the quarter with the Celtics ahead 18-11 with 3:59 left. On one play, he sprinted like a wide receiver and hauled in a long pass from Garnett ahead of the field and drove for an easy layup.
The rest of the game was far from easy for Boston, even with New York missing two of its top three players.
"In a tough game like this, coming down the stretch, coming down to the wire, I think it gives (our) guys momentum," Anthony said.
Based on reporting by The Associated Press.