Dennis Johnson's 22-foot jump shot at the buzzer gave the Boston Celtics a 107-105 victory over the Los Angeles Lakers tonight, evening the best-of-seven National Basketball Association championship series at two games each. Game 5 will be played here Friday.

The game was tied at 103 with 33 seconds remaining when Danny Ainge's long jumper put the Celtics ahead.

After the Lakers took a timeout, Kareem Abdul-Jabbar of the Lakers missed a sky hook. Teammate Magic Johnson rebounded and tied the score with 17 seconds left.

After a 20-second timeout, the Celtics walked the ball slowly up the floor for the last shot.

"We didn't know who would take the shot," Cedric Maxwell of the Celtics admitted. "Over in the huddle, some guys were looking and some guys were looking away."

"I wanted to take the shot," Dennis Johnson said after the game. He said the final play was designed "to take the clock down to five seconds, and have Larry (Bird) come off a pick."

With five seconds left, Johnson passed to Bird, double-teamed near the foul line. Bird passed back to Johnson. There was no more time to pass.

"I saw Byron (Scott) and Kareem coming," Johnson said, "and figured I'd make the shot a little higher. It felt good. I figured it had a 50-50 chance of going in."

"My only thought was just to watch the spin on the ball and see if it went in," Boston Coach K.C. Jones said. "I was just like everybody else in the place."

"I just took it and it hit all net," Johnson said.

"We were sagging down in the middle because (Kevin) McHale had hit his last seven shots," James Worthy of the Lakers said. "They were patient passing the ball around and working for the shot they wanted. It's unfortunate we didn't have a hand in his face."

"The last play was something we do all the time," Magic Johnson said. "We just lost a tough game at the buzzer. All we can do is forget this game and look ahead to Friday."

The Lakers appeared to have won with an 11-2 run midway through the third quarter.

"That's what I like best about us," Dennis Johnson said. "When we're pushed into the trenches, we know how to fight our way back out."

"I've said all along that each victory would be a tough one and tonight proved me right," Abdul-Jabbar said. "We didn't kick it away. They just hit more big shots than we did at the end."

"It feels somewhat like a dagger in the heart," Lakers Coach Pat Riley said. "Now we have to come back strong on Friday and take care of business. We had a chance to open it up and we didn't."

This game, decided by skill rather than elbows, was enlivened by brilliant performances, Dennis Johnson's perhaps foremost among them. He scored 27 points, one fewer than McHale and one more than Bird. Abdul-Jabbar led Los Angeles with 21 points.

Despite all the talk about rough play, the opening half of the first quarter was surprisingly sedate. Neither team seemed especially eager to throw its collective weight around.

With 6:12 to play in the quarter, the score was 16-14, Los Angeles. But Bird appeared to have regained his shooting eye, making three of his first four shots. The last of those baskets drew the Celtics to 18-16, when the Lakers got a boost from Scott, their leading scorer this postseason.

But he hadn't helped much in this series until he scored five consecutive points to give the Lakers a 23-20 lead. The quarter ended, 32-28, Lakers.

Boston took a 34-32 lead in the first two minutes of the second quarter, thanks to McHale, Bird and Dennis Johnson, and Johnson's shooting pushed the lead to 46-42. After eight assists in the opening 12 minutes, he had six points and an assist in the first six minutes of the second period.

The Lakers trailed, 51-48, with 3:18 to play in the half, and, not coincidentally, had been outrebounded by 23-14. McHale had seven. Maxwell scored the last three points for the Celtics before halftime and the team went to the locker room with a 59-58 lead. Dennis Johnson had 18 points by then and Magic Johnson 14 for the Lakers.

The Celtics opened the second half by taking a 65-58 lead.

But soon, Magic Johnson was going the length of the court and the Lakers surged ahead, 68-67, and the Celtics were spending a timeout.

The break didn't slow the Lakers, who scored another four points, inciting the sellout crowd of 17,505. By the time Boston called time, it was 72-67, Lakers, with 6:11 to play in the period.

Fittingly, it was Dennis Johnson who broke the spell. With two minutes left in the period, Los Angeles led, 80-76, McHale and Johnson keeping the visitors close. McHale scored six of Boston's next 10 points.

By the time the quarter ended, he had scored 13 points in the period, and the Lakers' lead was down to 84-82.

The Celtics had lost two straight, but not since November 1983 have they lost three in a row.

"It's even both numerically and emotionally," Riley said. "We have a chance to win Friday night, and I think we will, and then we just have to go back to Boston and win the championship."