Moses Malone demonstrated again today why he is the most dominant player in the National Basketball Association, carrying the Philadelphia 76ers to a 105-102 victory over the New York Knicks and a four-game sweep of their Eastern Conference semifinal playoff series.

Malone had what he described as a weak first half, but when the game was on the line in the final period, his performance made the difference and he had the Madison Square Garden crowd of 15,457 marveling at his prowess.

Malone scored 23 of his 29 points in the second half, 14 in the final quarter. In one 4 1/2-minute span of the last period, he controlled the game at both ends of the floor when he scored 10 points, blocked two shots, had six rebounds and intimidated every Knick who dared come near.

With the victory, Philadelphia advanced to the conference final against the winner of the Boston-Milwaukee series. The Bucks beat the Celtics, 107-99, in Milwaukee today to take a 3-0 lead in that best-of-seven series. Game 4 will be played Monday in Milwaukee. The NBA said that next Sunday is the earliest the final series will begin.

That schedule will be fine with the 76ers because two more players joined their injured list today. Point guard Maurice Cheeks sprained his right ankle in the final two minutes of the game and had to be carried from the floor. The injury is not considered serious and the team said he will be ready by Sunday. Backup center and power forward Cleamon Johnson pulled his left hamstring in the first half. His status is uncertain.

Andrew Toney missed one game and hobbled through the other three with a thigh contusion.

"Obviously I'm pleased we could win this in four games," said 76ers Coach Billy Cunningham. "Our biggest concern right now is we have some people injured. We just have to wait and hope they respond like Moses did. With all of the people we have hurt, the longer we wait for the next series, the better it'll be."

Malone had missed the last four regular season games because of two very sore knees. But he was dominant in this series, averaging 31.2 points and 15.5 rebounds.

"I didn't do much in the first half and I knew if we were going to win, I had to do more than I was doing," he said.

The score was tied at 90 when Malone finished off the Knicks. His defensive rebound resulted in two free throws for teammate Reggie Johnson. Then, after grabbing another rebound, Malone made two free throws. On New York's next possession, he blocked a shot by Len Robinson and started a fast break that Cheeks scored on.

Then Malone accounted for eight straight points. He scored on two fallaway jumpers, a power move in the lane and one crunching slam dunk off a rebound.

"The reason Philadelphia is so awesome is because of the man in the middle," said New York Coach Hubie Brown. "Moses put on an awesome display. When the game was hanging out there, he blocks three layups and they convert all of the them the other way and he gets all the rebounds. He's such a disruptive force on the opposition."

Julius Erving had 18 points, but even he got out of the way to let Malone work. "Every time they made a run at us, Moses was there," said Erving. "He's the franchise. He showed it this whole series."

The Knicks made two three-point shots after the outcome had already been decided to make the final score deceptively close.

Bernard King scored 15 points in the final quarter and finished with a game-high 35 for the Knicks.