More and more, it seems the National Basketball Association's best hope against the Bullets is that Dick Motta's guys miss the instructions on the blackboard, "WAKE-UP, 6:45 a.m.," trainer John Lally wrote after tonight's 112-108 victory over the Milwaukee Bucks.

If Elvin Hayes, Bobby Dandridge and Kevin Grevey oversleep the up-with-dawn call and can't get home for Wednesday night's game against Boston, maybe-just maybe-the Celtics will have a shot against the world champions, who tonight won without Wes Unseld and Tom Henderson.

Unseld has bronchitis and Henderson a strained knee. They didn't eve make this trip. Yet the Bullets seemed omnipotent. Once ahead by 13 points, later down by 11 to a Milwaukee team inspired by its 32nd sellout of a mediocre year, the Bullets made up an eight-point deficit in the fourth quarter.

They did it with Grevey, back in the starting lineup for the first time in nine games, scoring 10 points in the last period; with Dandridge, playing Mr. Inside to Grevey's Outside, getting another 10, and Hayes, Mr. everywhere, adding nine.

Hayes wound up with 29 points and 15 rebounds in a 46-minute night of work. That may sound spectacular but is, in fact, the recent norm for the astonishing veteran striving for the league's most valuable player award. Over the last dozen games, Hayes is averaging 25.3 points and 14.3 rebounds.

Grevey had 22 points on nine-of-18 shooting and showed no signs of the hamstring injuries that put him on the sidelines three weeks ago. After the game, his right thigh was wrapped tightly but, Grevey said, only as a precaution.

"It's just a little tight," he said.

The victory and Seattle's 106-102 loss to Portland tonight assured the Bullets of the home-court advantage throughout the playoffs. The full $50,000 bonus that goes to the team with the best regular-season record is only one Bullet victory or one Seattle loss away.

In the last 10 minutes of this game, the Bullets earned the victory with a precise offense and a defense that forced Milwaukee into ugly shots.

Dandridge, who made only two of his first 10 shots, had just eight points when Milwaukee owned a 91-86 lead early in the fourth quarter. By then, his opposite number for the Bucks, the gifted Marques Johnson, had 20.

Guard Brian Winters, firing from Lake Michigan, had 10 points and Johnson eight in a Buck splurge late in the second quarter and early in the third. In that spree, the Bucks out-scored Washington 34-12 and went from 11 points down to 11 up.

But at 91-86 it all changed. Motta went to his third-string center in the fourth quarter, bringing in rookie backup, Mitch Kupchak. While Kupchak can score-he had 13 points in 21 minutes-the Bullets' offense seems hopelessly perimeter-bound unless the center is setting picks and passing the ball, a la Unseld.

That, Corzine did.

Grevey and Dandridge did the rest.

The Bullets outscored Milwaukee, 14-2, in four minutes and three seconds, erasing that 91-86 deficit and going ahead to stay at 100-93.

Grevey scored three buckets in there, all 15-footers, and Dandridge had the other eight points-two coming on a nifty cross-under fast-break layup against Johnson's defense.

"I felt I could beat my man," said Grevey, who had scored 20 points in his first two games as a reserve after the latest hamstring pull. "And if I didn't have the shot, I gave it to Bobby down low. It was like a 1-2 punch and it became a chain reaction. We were executing our offense very well with Dave Corzine setting nice picks and getting us the ball."

Motta, now one victory into his second 500 as a professional coach, blamed himself for the club's erratic play in the first half.

"I used too many combinations," he said, speaking of his substitutions with the nine available men.

In the second half, Motta did not use guard Phil Chenier and forward Greg Ballard played only two minutes. That left the burden on seven men. Dandridge going all 24 minutes, Hayes working 22 and Grevey 20.

"It's a helluva tribute to the players," Motta said of the nine-man performance. "We stayed with the offense. We didn't panic. And we played defense about as good as we could play."

In other NBA action, George Gervin scored 46 points, 29 in the first half, to lead the San Antonio Spurs over the Cleveland Cavaliers, 116-112, in Richfield Ohio. In Chicago, Los Angeles rallied from a 27-point deficit behind Kenny Carr, who scored seven points in the final 3 1/2 minutes to help Los Angeles edge the Bulls, 97-95. The Lakers trailed by as many as 27 points in the game. Calvin Murphy's 29 points helped the Houston Rockets get by the Knicks, 116-115, in New York, Spencer Haywood and Gale Goodrich scored 26 points each to lead the New Orleans Jazz past Boston, 141-125, in New Orleans. Golden State turned back visiting Detroit, 104-100.