While everyone else was running around in a state of confusion in the final seconds, Bobby Jones came up with the biggest play of the game today, earning the Philadelphia 76ers a 107-105 victory over the Boston Celtics and a 3-1 lead in their best-of-seven NBA Eastern Conference championship playoff series.

Jones, one of the NBA's best defensive players, hurried up the court after missing a shot from the baseline with 10 seconds left to intercept a long Tiny Archibald pass intended for Larry Bird.

Jones cut in front of Bird and there was contact that sent Bird sprawling out of bounds. No foul was called. Bird said later, "We collided, but he had a better angle on the ball. There was no foul. At least, if I was the referee, I wouldn't have called one."

That play by Jones dashed a brilliant Celtic comeback that saw the visitors make up a 19-point first-half deficit, much to the dismay of the sellout crowd of 18,276 at the Spectrum. In the third quarter, Boston shot 67 percent and outscored the 76ers, 31-17.

The game went down to the final two seconds, although neither team scored a point in the final 72 seconds. The 76ers got their last points on two Julius Erving free throws with 2:39 left for a 107-103 lead. They had three more possessions: an Erving miss, a Bobby Jones miss and an unforgivable 24-second violation. Archibald scored on a fast break with 1:12 remaining for Boston's final points. Then it got frantic.

The 76ers called a timeout to set a play for Darryl Dawkins, but they tried to run it from the wrong side of the floor "and messed it all up," Coach Billy Cunningham said.

Before they could straighten themselves out, the 24-second clock had expired and the Celtics got the ball back with 48 seconds to play, trailing by two points. They took the first good shot they got, a 12-footer by Robert Parish, but it missed and Erving rebounded with 34 seconds left.

The 76ers wanted to run off as much time as possible, but the only shot they could manage was an off-balance short baseline jump shot by Jones that was offline. Boston's Cedric Maxwell got the rebound with eight seconds remaining.

Maxwell passed quickly to Archibald. Boston Coach Bill Fitch was up screaming for a timeout, but Archibald didn't hear or see him and hustled the ball up the court. He saw Bird open in the corner and tried to lob a 30-foot pass to him.

Enter Bobby Jones.

"As soon as I missed the shot I just took off," said Jones. "I knew they were going to go to Bird. I looked up and saw him drifting to the corner so I tried to get to a spot halfway between."

Jones looked up, turned, leaped and intercepted the pass. "I didn't even see it until the split second before I caught it," he said.

"He made a great play," Bird said. "When the shot went up at the other end, I took off. I was open and Tiny made the right play, but Bobby came up with a super individual effort and we came up short. If I had got the ball, I was going to take it straight to the basket, because there was a path. bI think there was time."

Fitch said that even though he wanted Archibald to call a timeout, Archibald has the option not to.

The 76ers began the game as if they were going to humiliate the Celtics. They harassed Bird into missing seven of his first eight shots and held him to six first-half points. They had outscored the Celtics on fast breaks, 22-6, and seemed to have the game under control.

"I told our guys at halftime, though, that Boston would come back," Cunningham said.

The Celtics used a 12-0 scoring spurt late in the quarter to close within three, 82-79, going into the final quarter. Chris Ford had 10 and Bird eight points in the quarter.

The Celtics led once in the fourth period, 84-83, after a jump shot by Archibald and a free throw by Rick Robey. Philadelphia then scored eight points in a row. Dawkins made two long jump shots and two free throws and Jones scored on a drive.

Erving was the high scorer for the 76ers with 20. He also blocked five shots and had five assists. Jones had 18 points and Andrew Toney 17.

Bird found his shooting eye in the second half and finished with 20 points. He also had 17 rebounds, six assists and three blocked shots.

The fifth game will be played Wednesday at Boston Garden.