For the first time in 46 games, the Washington Capitals have beaten Scotty Bowman. The Capitals disposed of that incredible jinx along with a five-game winless streak last night at Capital Centre when they defeated the Buffalo Sabres, 3-2.

It was a fitting moment for revenge, since a victory would have been Bowman's 690th and would have tied him with Dick Irvin as the winningest coach in National Hockey League history.

Goals by Bob Carpenter, Bryan Erickson and Mike Gartner made the difference, along with the 22-save goaltending of Pat Riggin and a controversial ruling that wiped out an apparent tying goal by Buffalo at the end of the second period.

Bowman had 30 victories and two ties against Washington while coaching Montreal, and had posted 12 triumphs and one tie with Buffalo before last night.

It may be said of Bowman that he went down fighting. He was standing on the bench and leaning out the gate to complain to referee Ron Fournier, even before the no-goal ruling that left Washington ahead after two periods, 2-1.

When the game ended, Bowman marched across the ice to talk with timekeeper Phil Mattingly. Then he spent 15 minutes outside the officials' dressing room in discussion with supervisor of officials John Ashley.

The subject was a shot by Buffalo's Mike Foligno that was deflected past Riggin just as the second period ended. Instead of the red light signifying a goal, the jubilant Sabres were greeted by a green light denoting the end of the period.

Referee Ron Fournier, after a discussion with his linesmen and goal judge Gus Connery, ruled that the period ended before the goal was scored.

"Trying to reconstruct it, there certainly was a lot of doubt," Bowman said. "The last time I looked at the clock, when he was shooting, it said two seconds. The ref said he had to rely on the goal judge. But after the game, the supervisor told me the back linesmen was supposed to watch the puck and the clock, and that procedure was followed."

Washington Coach Bryan Murray, who had shouted some unkind words at referee Don Koharski following the Sabres' 3-2 victory in Buffalo Friday night, had a chance to chuckle at someone else's distress.

"Last night we felt we had a beef," Murray said. "He obviously felt he had one tonight. It's nice to have another coach screaming for a change. But I'm still upset about last night. We could have had three or four points against this team."

On past history, Murray should settle for the two. This was Washington's third victory over Buffalo in 43 meetings and the first since April 4, 1978, about the time Murray was deciding to give up coaching to become a businessman in his hometown of Shawville, Quebec.

The Sabres jumped on top last night, Ric Seiling connecting on a rebound of Gilles Hamel's shot. Washington's Larry Murphy was in the penalty box at the time and the score maintained Buffalo's record of at least one power-play goal in every game this season.

The tide turned with 32 seconds left in the first period, as Carpenter deflected Gartner's shot for his 12th goal of the season.

"I was in front with Seiling and we kept hitting each other," Carpenter said. "When Mike shot, I waved my stick up and down and I felt something hit it. At first, I thought maybe Seiling hit it, but I guess the replay showed it was the puck."

Thirty-six seconds into the second period, the Capitals went ahead to stay. Rod Langway broke up a Buffalo rush at his blueline and fed Alan Haworth to start a three-on-one break.

Larry Playfair, the lone defender, got his stick on Haworth's pass and the puck skidded to Dave Christian, who fanned on a shot. However, his swing pulled goalie Tom Barrasso out of position and when the puck rolled along to Erickson, Barrasso had no chance.

"It was just an open net for me," Erickson said. "It went off the heel of David's stick and came right to me."

Except for Foligno's belated blast that went for naught but controversy, there was no further scoring until the midpoint of the third period, when Gartner converted Gary Sampson's pass out of the right corner for his 11th goal.

"I was in front of the net and Larry Murphy threw the puck across and I shot it wide," said Gartner, whose scoring streak reached 15 games. "Then Gary Sampson got it and threw it back and that time I put it between the goalie's legs."

Gartner's goal marked the first time in 10 games the Capitals had scored three against Buffalo. They had two in each of the nine previous games, of which eight were lost and one tied.

There was to be one more goal, registered by Buffalo's Phil Housley with six seconds left, after he picked off a pass by Langway. It did nothing but magnify the importance of the earlier no-goal decision.