The Washington Bullets won their first game of the season last night, holding the Detroit Pistons to three points in the final six minutes for an 86-82 victory before 6,817 at Capital Centre.

Bullet center Rick Mahorn got a key offensive rebound and made two free throws in the last 17 seconds to assure the victory. He finished with 19 points, 11 rebounds, three blocked shots and praise from Coach Gene Shue.

"He's one of our leaders," said Shue, "and we have to depend on him a great deal."

The Bullets had lost their first three games while the Pistons were winning their first three.

Washington trailed by as many as nine points in the second quarter and was down by four, 71-67, early in the final period. But Detroit missed its next 10 shots and fell behind, 76-72. Then Edgar Jones' three-point play, Phil Hubbard's driving layup, Terry Tyler's 18-foot jumper and another free throw by Jones gave the Pistons an 80-78 lead with 4:52 remaining. The Bullets' only points during that spurt came on a layup by Don Collins.

But the Pistons had gotten their last field goal with 5:55 to play. They missed their last five shots, lost the ball four times and made only three of six free throws.

The Bullets tied at 80 on Greg Ballard's two free throws and, after Jones made his free throw, Ballard sank a long jumper from the right corner for an 82-81 Bullet lead. Two free throws by John Lucas with 1:26 to play increased the margin to 84-81.

Isiah Thomas, the Pistons' heralded rookie, made one of two free throws with 43 seconds left, then the Bullets ran the clock down to 20 seconds before Lucas tried an off-balance, running one-hander. The ball bounded off the rim to Detroit's Kent Benson, but before he could corral it Mahorn snatched it away. Mahorn's two free throws with six seconds left, after he was fouled by Kelly Tripucka as the Bullets played keep-away, ended the suspense.

Detroit made only four of 18 shots in the last quarter, 38 percent for the game.

"Our defense was sensational," said Shue. "We were as aggressive as hell. They shot so poorly in the final period because we were forcing them to shoot from so far out.

"I'm very, very pleased with the way we played. Our players wanted this game badly and they played like it. We wanted to get off that losing streak. We just have to keep stressing the defense and refining the offense. We still have some uncertainty and hesitancy on our passes, but we'll get better as people get more used to each other."

Thomas, who had been averaging 24.7 points and 6.3 assists, led the Pistons with 20 points.

Collins scored in double figures as a reserve for the fourth straight time. He made seven of 10 shots for 14 points. Teammate Jim Chones didn't get into the game and his streak of having played in 529 straight, second-longest among active players, was broken.