Sidney Moncrief last night showed why he is among the best all-around players in the National Basketball Assocaition.

With Bob Lanier and Dave Cowens sidelined with knee injuries, it has been Moncrief and Marques Johnson who have led the Bucks (39-19) to the fourth-best record in the league. Last night, before 6,781 at Capital Centre, Moncrief scored the Bucks' last nine points and had a steal and dunk with six seconds left to give Milwaukee a 101-99 victory over the Washington Bullets.

"Most of our plays down the stretch are going to me or Marques," said Moncrief.

Moncrief, a 6-foot-4 guard-forward from Arkansas, finished with 33 points, six rebounds and four assists. He made 13 of 17 from the foul line and scored 14 points in the final quarter as the Bucks rallied for their third straight road victory.

The Bullets couldn't do much better at home than on the road as they lost for the sixth time in seven games. This was the first time they had played at Capital Centre since they beat Houston Feb. 10.

The defeat dropped the Bullets to 25-31 and even deeper into the Atlantic Division cellar.

Jeff Ruland, despite a very sore calf, scored 25 points and had 15 rebounds and Rick Mahorn broke out of a long slump with 14 points, six rebounds and two blocked shots.

The Bullets were leading, 93-92, with 2 minutes 33 seconds remaining when Moncrief took over. First he made one of two free throws after being fouled by Ruland to tie the score. Then, after Alton Lister blocked a shot by Mahorn, Moncrief was fouled by Frank Johnson, and this time he made two free throws for a 95-93 Milwaukee lead.

Ruland tied the score on a hook shot with 34 seconds left and the Bucks called successive timeouts, the first a mistake and the second to get the ball at midcourt.

Lister inbounded to Johnson, who lobbed to Moncrief, who had position on Ricky Sobers. Moncrief made the layup for a 97-95 Milawaukee lead with 31 seconds left.

"We wanted a quick shot, but Marques made a great move when he got the ball and Ricky (Sobers) got caught on the wrong side of me. I got the inside position and Marques just lobbed the ball in perfectly," said Moncrief, who laid the ball in over the front rim with no Bullet around him. "We run that play very well."

After a timeout, Moncrief intercepted Charles Davis' inbounds pass intended for Sobers and drove half the length of the court for a dunk that sealed the victory. Frank Johnson made a meaningless three-point shot at the buzzer.

Moncrief didn't score until the Bullets had built a nine-point lead late in the first quarter. He scored 24 in the second half. "I came in at halftime and told myself I had to get more aggressive," he said.

In addition to Lanier and Cowens, the Bucks were also without Junior Bridgeman, who has a sprained ankle; thus, a majority of their offense was geared to Moncrief and Johnson. Johnson finished with 22 points.

Bullets Coach Gene Shue was pleased with his team's showing, in spite of the result. "We got good performances from Jeff and Ricky, but we had a bad rotation."

Spencer Haywood wasn't with the team because he was with his wife, Iman, who underwent surgery in New York after being in an automobile accident last week.