Just when it looked as if they were dead and buried, the Boston Celtics crept out of the grave by scoring the game's final eight points to overtake the Philadelphia 76ers, 111-109, tonight, to stay alive in the NBA Eastern Conference championship playoff series.

The Celtics still trail, 3-2, in the best-of-seven series, "but at least there's a tomorrow now," said Larry Bird.

Bird was his usual incredible self, scoring 32 points and collecting 11 rebounds, five assists and three steals, but it was the energetic M. L. Carr who was the Boston hero. He made three free and took down the two most important rebounds of the game, all in the final 20 seconds, to bring down the house and send many of the 15,320 at Boston Garden swarming onto the floor as if this game has been for the world championship.

It was those same fans who booed the same Celtics at halftime when they were down by 10 points.

The Celtics clawed their way back, and even led by five points late in the third period. But the 76ers refused to be intimidated by the Boston crowd or the Celtics and kept coming back. Four straight free throws by Darryl Dawkins put the 76ers on top by six, 109-103, with 1:51 remaining, and 11 seconds later Dawkins stole a Bird pass intended for Robert Parish and a hush fell over the Garden.

The Celtics wouldn't quit, though.

Andrew Toney, the high-scoring 76er rookie, who finished with 20 points, missed a short jumper and then fouled Tiny Archibald at the other end as the little Boston guard drove by him and scored a layup. Archibald's successful three-point play cut the Philadelphia lead to 109-106 with 1:20 left.

Toney again tried to do it himself and this time 7-foot Parish blocked the 6-3 guard's shot. Bobby Jones retrieved it, but lost it out of bounds with 33 seconds to play.

Bird wasted no time going to the basket, scoring on a drive down the middle eight seconds later to get the Celtics to within a point, 109-108.

That's when Carr made his presence felt and the Celtics, as a team, applied so much defensive pressure that the 76ers lost their cool for the only time all night.

It took Bobby Jones three tries before he successfuly inbounded the ball, but before the Sixers could get off a shot, Cedric Maxwell knocked the ball away from Julius Erving and out of bounds with five seconds left on the 24-second clock and 28 seconds left in the game.

Inbounding the ball from the baseline, Erving threw it low and behind Bobby Jones. It rolled upcourt toward the Celtic basket. Bird beat everyone else to it and took off for the goal. His running one-hander was too high off the glass, but Carr, who was a defensive replacement for Chris Ford and hadn't played at all in the second half until the final two minutes, was there to take the rebound between Dawkins and Erving. He went back up with the ball and was fouled by Erving with 20 seconds to play.

He made both free throws for a 110-109 Boston lead.

The 76ers had plenty of time to get a good shot, but Bobby Jones, the here of Sunday's Philadelphia victory, couldn't make the magic tonight. His short left-handed jumper in the lane was short, bouncing off the front rim to -- of course -- Carr, who was immediately fouled by Erving in the backcourt.

The 76ers were in the penalty situation, so Carr had three chances to make two. With only a second remaining, Coach Bill Fitch instructed him to make one and miss the others, assuming the one second would expire while the ball was loose. It didn't.

Carr made the first, missed the second and third, but Dawkins grabbed the rebound and called a timeout before the second ticked off the clock.

That gave the 76ers the ball at midcourt, but Bobby Jones, who had an uncharacteristic five turnovers for the game, couldn't find anyone open when he tried to inbound the ball and ended up throwing it to Parish as the game ended.

Archibald scored 23 points and Carr finished with seven.

Lionel Hollins led the 76ers with 23 and Erving and Dawkins had 21 each. Erving failed to score in the final quarter.

The 76ers also lost guard Maurice Cheeks in the first 10 minutes. After a collision while going for a loose ball, Cheeks had a severe headache and dizzy spells and didn't play anymore. The 76ers said he would be taken to a Temple University Hospital as soon as the team arrived home late tonight.

The sixth game of the series will be played Friday night at the Spectrum where the Celtics have lost 11 straight times in the last two seasons. If a seventh game is necessary, it will be played Sunday afternoon at the Boston Garden.