BOSTON - Like everything else in this frigid area, Willie Green froze. Paul Pierce launched a shot in the waning seconds that could have won the game, and the way the 76ers season has gone so far, a swish, a loss and a long trip home seemed to be in their immediate future.

Pierce's shot instead fell off to the left of the rim, somehow landed in the hands of Ray Allen, who then launched an off-balance three pointer that also missed.

Improbable final score: Sixers 98, Celtics 97.

It was the first loss in 12 games for the Celtics, who dropped to 20-5, including a 1-4 mark in Friday night home games. Who can figure?

The Sixers won for only the second time in 15 games in improving to 7-19. They played without Allen Iverson, who was back in Philadelphia tending to an arthritic left knee. They got key performances off the bench from Elton Brand and Marreese Speights, who combined on the play toward the end that won the game.

Kevin Garnett (21 points) made two foul shots with 23 seconds left to give the Celtics a 97-96 lead. After a timeout, the Sixers worked the ball to Speights (17 points, 10 rebounds) who missed a tough 15-footer over Kendrick Perkins. Brand slipped inside and tipped the ball in with 7.7 seconds left for the deciding points. When Pierce and Allen couldn't connect, the Sixers ran off the TD Garden floor like a bunch of jubilant kids.

"Truthfully, my heart sank a little bit and I just froze," Green said of watching Pierce's and Allen's shots. "There were only a couple of seconds left, but it felt like a minute. It was a good team effort. I thought Elton was big for us; Speights was big coming off the bench. Basically, as a team, we played well. These are things we have to do to win games."

It didn't look good early. The Celtics can run, they can shoot, they can pass, and they can defend. Not only were they the first team in the NBA to 20 wins this season, they also are one of the league's most exciting teams.

Last night, even the timeouts were exciting.

During a break in the middle of the second quarter, Philly native and Boston sub Rasheed Wallace was thrown out of the game by referee Bill Kennedy for jawing from the bench. During the next timeout, a Celtics fans hit a halfcourt shot and collected $50,000.

The Wallace ejection particularly hurt coach Doc Rivers' team in the second half. Without his top sub, the Celtics were outscored by Sixers, 56-44. Wallace, the former Simon Gratz star, had posted 30 points in 46 minutes the last two games combined. It was his first ejection of the season, for getting his league-leading ninth and 10th technicals.

Boston started the game slowly, making only nine of 23 shots in the first quarter, but it still posted a 24-17, largely because of a 20-10 rebounding advantage.

After a layup by Speights closed the gap to 25-21 early in the second, the Celtics went on a 21-10 run for a 46-31 lead, their biggest of the game. During that spree, Boston shot 9-for-12.

But the Sixers continued to grind and finally got their first lead of the second half on two foul shots by Brand to make it 86-84 midway through the fourth. The lead changed six times from then on, the last being on Brand's game-winning putback.

"That was being at the right place at the right time," said Brand, who finished with a team-high 23 points in close to 27 minutes off the bench. "Speights got the ball, and you know he wasn't gonna pass. He doesn't pass. So I ducked in to get the ball, went to the offensive glass."

And ultimately gave his team its best win of the season.

Green (16 points) started in place of Iverson. The Sixers have had nine different players start this season. Boston, on the other hand, has had the same starting five for the entire season. In fact, starters Rajon Rondo, Allen, Pierce, Perkins and Garnett are now 105-29 in starts together since the 2007-08 season.

Andre Iguodala finished with 18 points, eight rebounds and four assists for the Sixers, despite still being hindered by sore ribs on his left side.

Allen scored 17 for Boston, while Rondo had 13 points and 10 assists.

The Sixers are close to becoming a fully healthy team for the first time in a long time, as Lou Williams should return from his broken jaw in the next week, and Iverson also should be back during that time frame. Speights played in only his second game after missing a month with a knee injury. It is a luxury coach Eddie Jordan is eager to deal with.

"Marreese is a big part of what we did early in the season," Jordan said. "He's back; Lou's going to be back probably by the end of next week; Allen's going to be back by the end of next week. It's good to have a full deck of cards to play with."

Six shots

Allen Iverson could be out for more time than originally thought. Coach Eddie Jordan said yesterday morning after the shootaround that Iverson, whose arthritic left knee was drained twice this week, would be back for tonight's home game against the Los Angeles Clippers. Then in his meeting with reporters before the game last night, Jordan said Iverson could be out until the team plays in Utah on Dec. 26. After Jordan's comments, a Sixers official said: "There is certainly a possibility that he could be out until Utah. It depends on what Dr. Jack [McPhilemy] says and how he [Iverson] feels [today]. Is there a possibility he could play [tonight]? Yes, depending on how he feels. However, if he's not responding well, there is the thought process that maybe we hold him out [tonight] and Tuesday [in Washington] and let him get an extra week of rest, then bring him back for Utah." *