In their previous four contests, the Washington Bullets found themselves unable to maintain a halftime lead. Against the Celtics tonight at Boston Garden, they had no such problem.

Taking advantage of a series of mistakes by the visitors, the defending Eastern Conference champions raced to a 57-37 halftime lead, then had to sweat out a Washington comeback, finally hanging on for a 118-114 victory.

The loss extended the Bullets' losing streak to seven games. The team will get another chance to stop its slide against the Philadelphia 76ers on Saturday night at Capital Centre.

No matter what their record was, the Bullets would have had a hard time competing with Boston during the first three quarters of tonight's game.

The Celtics, now with eight straight wins after a season-opening loss to New Jersey, treated the 227th consecutive sellout crowd at the Garden to an on-court exhibition of such ever-welcome abilities as ball movement, fast breaks and a penchant for pouncing upon an opponent's weaknesses.

The final 12 minutes were another story entirely, however. Trailing by 19 points, Washington somehow became the dominant team. Center Jeff Ruland scored 18 of his game-high 30 points and added six of his 17 rebounds during that span. There was also a stretch of four three-point field goals by the Bullets (two each by Dudley Bradley and Jeff Malone) in the final minute of play, combined with six missed free throws by Boston.

However, the attempt at heroics just wasn't enough to overcome the large deficit.

"We dug ourselves such a large hole that it was hard to recover," said Washington Coach Gene Shue. "The Celtics played an excellent game, and even though we did make a good comeback, there was just too much cushion to overcome."

There also was the matter of too much Bill Walton. The 11-year veteran was forced into yeoman's duty when starting center Robert Parish went out of the game with a bruised arm. But the team didn't really lose much. Walton scored 19 points and had nine rebounds and four blocked shots in 28 minutes.

"I guess that's the reason they got Bill," said Boston guard Danny Ainge. "I don't want to see Chief (Parish) out too much, but it's nice to have the people to replace him."

Much of the Celtics' early cushion was built upon Washington turnovers. The Bullets were only charged with eight in the first half, but the official scorers were either being charitable or they simply weren't able to keep up with Boston's constant transitions from defense to offense.

Actually, the Celtics weren't in need of such largesse by the Bullets. The day before the game, Shue commented that he didn't consider Boston to be a great running team. In comparison with greyhounds like the Los Angeles Lakers, that's true enough, but there may be no team better than the Celtics at scoring a number of easy baskets.

Against Washington, it often started with defense. Whenever a member of the Bullets attempted a field goal from the outside, the defender would run at him, then break down court. Because of the visitors' 35 percent shooting and the Celtics' inside power, that often led to long passes and simple layups.

It was that economy of effort that perhaps lulled the Celtics into believing the contest was in the bag.

"We were thinking they'd fold over and die, but they came back," said Ainge. "They never did quit. We were up by a lot, but it was definitely a game at the end."

Going into and during the early portions of the fourth quarter, Shue constantly pressed upon his troops the idea that "anything can happen."

Almost everything did. The Bullets seemed more like pests than anything else, but suddenly, with six minutes remaining, the score was 96-86 Boston, a margin that Ainge would later say "is nothing for a team to overcome."

But even with their missed free throws, the Celtics just had too much manpower. A three-point play by Ruland was matched by a three-point field goal by Larry Bird. Bradley's first three-pointer came just seconds after Walton had provided a basket and free throw.

"Usually, it's us who start out fast and then relax late. Tonight it was them," said Washington guard Gus Williams.

"I think we showed some character tonight . . . Now we've been on both ends of the spectrum. I hope that we put them both together against Philly."