The Washington Bullets and Detroit Pistons continue what has come to resemble a never-ending fencing match. The Bullets' 108-100 victory tonight at the Silverdome wasn't very different from a Capital Centre encounter 11 days ago, nor from an overtime meeting here Nov. 12.

Back and forth, parrying and thrusting. There wasn't a time over the course of the game that either squad led by more than five points. It was tied after 12 minutes, tied at halftime and tied after three quarters. Detroit forward Kelly Tripucka hit 12 consecutive shots during one stretch in the second and third quarters but his streak was almost matched basket for basket by Washington's Dan Roundfield.

By game's end, Bullets Coach Gene Shue, who had wondered aloud recently what his team had to do to get a victory on the road, had found the answer in his squad's shortest player.

Frank Johnson, starting his second consecutive game for a flu-ridden Gus Williams, scored 27 points, nine of them in the final 2:45, to lead the Bullets to their third straight win and first road victory in eight games. Johnson also had 10 assists and six rebounds.

Washington (11-11), an even .500 for the first time since Nov. 2, received a big jolt late in the contest, however, when center Jeff Ruland, who had 22 points, 13 rebounds and six assists, fell to the floor in a heap, clutching his right ankle.

Ruland was taken to a Detroit hospital to be X-rayed and was diagnosed as possibly having a chip fracture in his right ankle. He was released and will return with the team to Washington, where he will be examined Thursday morning by the Bullets' team physician, Dr. Steve Haas.

The injury cast a pall over what was an outstanding win. Not only did the Bullets end their string of losses on the road, they maintained their poise and made more big plays than Detroit.

They also held the high-scoring Pistons, who entered the game averaging 118 points per game, to 16 points in the fourth quarter.

"In the third period we couldn't stop them and they couldn't stop us. But to then hold them to just 16 in the fourth quarter is just incredible," said Shue. "We took charge and the momentum."

That statement could be taken literally. With 3:12 to play in the game, Cliff Robinson (22 points) hit a jump shot from the left corner to give the Bullets a 97-96 lead, the first time since late in the previous quarter that Washington had been in front. Eleven seconds later, Isiah Thomas, the Pistons' all-star guard, was whistled for charging into Johnson.

At the 2:46 mark, Johnson made a shot from near the top of the key. Then, Johnson stripped Thomas (10 points, three-for-11 shooting) of the ball and cruised in for a layup that made it 101-96 with 2:31 to play.

"Anytime you can make that kind of play, steal a ball from Isiah, it's a big accomplishment," said Roundfield, who played for Detroit last season. "To do it late with a game on the line is especially great."

That's the type of night it was for Johnson, who returned to the team Nov. 27 after recuperating from a broken bone in his left foot. Since that time Johnson has played well but hasn't hit what he would consider "game shape." At one point in the first half, Shue wanted to substitute Dudley Bradley for Jeff Malone only to have Johnson insist upon coming out for a break.

"I'm not in great shape yet but I was glad to help out," Johnson said. "It came down to defense. It's always great when you have a guy like Manute Bol to help you out."

But even the 7-foot-7 Bol, who blocked seven shots, was helpless against Tripucka. Just when it appeared that there wasn't anyone in a Washington uniform that could stop him, Pistons Coach Chuck Daly did the job himself, placing the forward on the bench for the start of the final quarter and not re-inserting him until just over four minutes remained.

"They had some big people in and Kelly doesn't do as well against bigger lineups," Daly said. "Anyway, I thought Tony Campbell was doing a fine job for us."

Tripucka, who missed his only two field goal attempts in the fourth quarter, led his team with four rebounds in the final 12 minutes but the Pistons, just six for 22 from the field in the period, couldn't convert them into enough points.

Mainly, according to Robinson, because the Bullets wouldn't let them.

"We just beared down real hard tonight. We came in here to get the win," he said. "Not that we didn't the last time or at other places, but we're a good enough team that we should be able to win on the road. And tonight we tried to show it." Pacers 114, Spurs 101

Indiana, which scored only 64 points the night before, got 46 points from its bench and a season-high 28 points from rookie Wayman Tisdale against visiting San Antonio. Johnny Moore scored 30 for the Spurs. Hawks 105, SuperSonics 97

Dominique Wilkins keyed a 12-point run by Atlanta as the game opened and the Hawks coasted past visiting Seattle. Wilkins had six of his game-high 31 points then. Celtics 118, Kings 101

Larry Bird had 24 points, seven rebounds, five assists and four steals against visiting Sacramento before going out with 5:23 left in the third period. Boston guard Dennis Johnson apparently incurred a hairline fracture of his left wrist and will be idled indefinitely. 76ers 125, Cavaliers 110

In Philadelphia, Moses Malone scored 34 points and Julius Erving 23 against Cleveland. Perry Moss, in his first game for the 7634s, scored 12 points in the second quarter. Jazz 119, Trail Blazers 111

In Salt Lake City, Adrian Dantley scored 36 points and Karl Malone 20 to lead Utah past Portland. Nuggets 134, Clippers 95

Wayne Cooper scored 22 points and blocked a club-record nine shots for Denver against the visitors from Los Angeles. Suns 123, Warriors 113

Phoenix invaded Oakland and gained its first road victory in 11 tries this season as Walter Davis tied his career high by scoring 43 points against Golden State.