he Washington Capitals found themselves on the down escalator tonight. The march to the playoffs, so spirited 48 hours ago, took an abrupt about face as Washington was thumped by the Philadelphia Flyers, 7-1, for its worst defeat of the season, and Pittsburgh tied Calgary, 4-4.

That turn of events, combined with the Penguins' surprise success in Quebec Saturday, left the Capitals eight points behind and panting.

"We were intimidated by the situation," said Washington Coach Bryan Murray. "Some of the guys who had been playing so well came up with short legs. We didn't play well and it's a shame, after working so hard the last two or three months to get in position to make a run at the playoffs.

"Pittsburgh winning the way they did last night (Saturday) has to do something to you. I know I was disappointed and frustrated. That certainly was a game I had projected them to lose. I just hope that was it. We've got to bounce back and play tougher than ever now."

The Flyers skated out with a winless streak of four games, a record of one victory in the last nine and distant memory of their last Spectrum success on Feb. 14. They had fallen behind the New York Rangers and the fans' disenchantment was obvious, both from the hundreds of no-shows and a sign that read: "The 1982 Philadelphia Lay Down and Dyers--All Talent and No Guts."

The Flyers, wearing their orange road uniforms on sweater exchange night, kayoed Washington goalie Dave Parro with four goals in the first period, then padded their lead with three more against reliever Al Jensen. The Capitals did not spoil goalie Rick St. Croix's bid for Philadelphia's first shutout of the season until 2:24 remained, when Ryan Walter netted his 34th on a power play set up by Dennis Maruk.

St. Croix was sensational, particularly in the second period, when he stopped all 21 shots that came his way, including a flurry during overlapping penalties against Behn Wilson and Bill Barber.

"We had a chance to get back in it in the second period," Murray said, "but we had about two or three shots at open nets and he reached out and somehow knocked them away. The goaltending they got is what we have to get the rest of the way."

There was no early indication that St. Croix would approach invincibility. With the Flyers ahead, 1-0, Bobby Gould dumped the puck in from the red line and St. Croix skated out to try to scoop it up on a couple of bounces. It went right past him, hit a goal post and caromed through the crease and out of danger.

"I didn't even see it," Gould said. "I never imagined it might go in. Those things happen, where the puck takes a funny bounce. It's tough to play those. It's no real indication a goalie is shaky. I wish it was, but he sure wasn't shaky tonight."

What was shaky was Washington's play in its own end. The first Philadelphia goal came after Randy Holt was stripped of the puck a moment after he received a tentative, rink-wide pass from Darren Veitch. The second saw Barber beat Walter out of the corner, with the puck hopping onto Darryl Sittler's stick after Walter pried it away from behind.

On the third, Mike Gartner let the puck get away as he was challenged by Brad Marsh and it went right to Reg Leach for a quick shot. Brian Propp scored No. 4 while lying in front after Washington couldn't clear the puck.

Bobby Clarke was clearly over the red line on what should have been a two-line pass violation before he scored No. 5 on a breakaway. By then, it really did not matter, however, because this game was decided.

The Flyers checked everyone who passed or shot the puck, while hits in the other direction were rare, as the play resembled Washington's first 12 fruitless visits to this building, where they had won three of four before tonight.

"We were getting knocked down all over the ice and when we had a chance to bump them, we didn't do it," Murray said. "It was mentioned to them repeatedly, but they didn't respond."

For a last unhappy note, Bobby Carpenter was struck just below the left knee by teammate Bengt Gustafsson's shot in the third period and figures to carry a bone bruise into Wednesday's home game against Pittsburgh. Murray hopes his team carries a different attitude, too.