The Bullets, having taken care of the middleweights rather handily this weekend, now will step up in class and challenge heavyweights Boston and Philadelphia, beginning with the Celtics tonight at 8 in Capital Centre.

The Bullets play the 76ers Wednesday night in the Spectrum. The Celtics (48-15) and 76ers (45-17) have the best records in the National Basketball Association and are 8-0 against Washington this season. Each team has beaten the Bullets four times.

"They don't just beat us, you know," said guard Kevin Grevey. "They beat everybody."

The Bullets (31-31), bouyed by victories this weekend over Indiana, New York and Atlanta, all challengers for a playoff spot, say they are ready for the Celtics and 76ers.

"There's no awe associated with those two teams," said Grevey. "They're good, but on the right night we can beat them. To win will require us to play a super game and them to be a bit off. If we both play super they'll beat us because they just have more talent. We match up pretty well with both teams, but they can come off the bench with five or six guys as good as the ones they're replacing."

The Celtics have been proving that the last three weeks. They have won 11 straight, most of them without injured Larry Bird, Tiny Archibald and Chris Ford. The winning streak is their longest this season and second longest since Milwaukee won 12 straight earlier this winter.

Bird missed five games with a fractured cheek bone and has been the sixth man the last three games while Kevin McHale started. Archibald hurt ligaments in his right, non-shooting, wrist and missed 11 games, but has played the last two; Gerald Henderson has started the last 13 games for him. Ford missed two games with a sore back; 11 games ago, M.L. Carr stepped in and hasn't stepped out since.

Seven-foot center Robert Parish has been the standout in more than size, averaging 24 points and 11 rebounds the last 30 games. The Celtics have won five in a row on the road and hold the best road record in the league, 22-10.

"We almost beat them the last time, so we know we can play with them," said Bullets center Rick Mahorn, referring to Boston's 99-98 victory at Capital Centre Dec. 18. "We have to get them to play a half-court game. We can't let them run on us whenever they feel like it."

The Bullets have the fifth-best record in the Eastern Conference, where six teams make it to the playoffs. Going into tonight's game, the Bullets trail fourth-place New Jersey (33-32) by a half-game. The Nets are idle tonight and host San Antonio Wednesday. The Bullets are two games ahead of sixth-place Atlanta (29-33).