Several not-so-funny things happened to the Washington Capitals on their way through The Forum tonight. The Montreal Canadiens mugged them, 6-1, rookie goaltender Dave Parro reinjured his separated left shoulder and the Capitals even got the short end of the brawl that led to 180 minutes of penalties.

In fact, the only thing laughable about the Capitals's 20th straight loss at The Forum, where they have never won in their seven-year existence, was their power play. They are the National Hockey League's least productive team with a man advantage, and sadly demonstrated why to a national television audience on "Hockey Night in Canada."

Richard Sevigny, the rookie netminder who has not lost in 10 games in Montreal, stopped 20 of 21 shots and sent the Capitals home with a disappointing 0-3-2 record for their five-game trip, a two-game losing streak and a dent in their playoff aspirations.

"This was a crucial road trip for us, but by no means are we throwing up the parachute," said Coach Gary Green, who will have to regroup his squad and deal with the injury-muddled goaltending situation before the Capitals take on the Chicago Black Hawks at Capital Center Wednesday night.

The Capitals now are 19-24-14, with 13 of their remaining 23 games at home.

Parro dislocated his shoulder at Calgary 10 days ago but was pressed back into action when No. 1 goalie Mike Palmateer bruised his left hand in the first period of Thursday's 6-3 loss in Buffalo. Parro aggravated the injury when he dived in a vain attempt to prevent Montreal's fourth goal. This was at 10:53 of the second period, as the Canadiens scored on a power play for the second time in 50 seconds.

Parro, facing the Canadiens for the first time, brought a 2.81 goals-against average into the game and made six saves in the first six minutes.

But at 6:41, Pierre Larouche took a pass from defenseman Larry Robinson -- back in action after sitting out his All-Star Game invitation with a blood disorder -- and rifled a shot past Parro from the top of the left face-off circle. Three minutes later, Larouche set up Guy Lafleur with a perfect pass. Lafleur, hampered by an eye injury but tonight the game's No. 1 star, got his 15th goal of the season, from the middle of the left face-off circle.

The second period was especially depressing for the Capitals. At 8:27, Hangsleben was sent off for another two minutes for delay of game and, with 29 seconds remaining in his penalty, rookie Jim McTaggart committed the same maddening violation.

It took Montreal, with the two-man advantage, just five seconds to score, Lafleur taking the faceoff and passing to Robinson, whose slap shot from the right point was on target. Fifty seconds later, as if to give the Capitals a much-needed lesson in power play opportunism, Rejean Houle, rebounding Lafleur's slap shot to the left of the goal and jamming it home.

That was the play that finished Parro. His shoulder was too strapped to top out of its socket again, he said afterward, but it was "pushed up" into already painful muscles.

Back-up goalie Wayne Stephenson, still nursing a sore back, held the Canadiens scoreless the rest of the period. But they stretched the lead to 6-0 on third period goals by Doug Risebrough (a 20-foot breakaway, his 100th NHL goal) and Steve Shutt.

Washington captain Ryan Walter, who elected to play even though he had been ill most of the day with a fever and stomach discomfort from suspected food poisoning, ruined Sevigny's shutout with a goal at 15:56.

The final period was interrupted for 15 miniutes by a brawl started when McTaggart checked Lafleur behind the net, and Montreal's Chris Nilan, coming off the bench as both teams changed lines, went after him.

When a lineman tried to separate the pugilists, Nilan lifted him up and moved him down the ice to get back into the gray, which escalated into a bench-clearer as the crowd of 17,139 howled. Five Canadiens and seven Capitals were penalized, with Nilan getting two two-minute minors, one five-minute and one 10-minute major and two game misconducts.

Larouche, Houle, Robinson and Mario Tremblay also got major penalties for Montreal, but McTaggart, Hangsleben, Rick Green, Bengt Gustafsson, Wes Jarvis, Jean Pronovost and Paul Mulvey all got majors for Washington. The Capitals finally on a power play goal, their first success in five tries, but the discrepancy in majors left tham on the short end of the brouhaha.