In perhaps their most remarkable accomplishment of a fairy-tale season, the Washington Capitals overcame a lengthy casualty list last night at Capital Centre and outskated the Philadelphia Flyers, 4-3.

Goalie Al Jensen stopped 35 shots and a makeshift defense of Rod Langway, winger Ken Houston, Greg Theberge and Paul MacKinnon held off the NHL's best team over the last 27 minutes after Randy Holt was ejected.

The Flyers, whose last score came with eight seconds left, were losing for the fifth time in the last 33 games; three of those defeats have been inflicted by Washington.

MacKinnon, who was recalled from Hershey Thursday, turned in an outstanding defensive game, as he and Theberge went shift after shift without yielding an opposition score. MacKinnon also produced the goal, his fifth in the NHL, that put Washington ahead to stay.

Goals by Bobby Clarke, in the first minute of the game, and Bill Barber, in the first minute of the second period, had the Flyers in front, 2-1, at the midpoint of the game.

Milan Novy tied it at 10:15 of the second period, on a deflection of a Doug Jarvis shot. Fifty-nine seconds later, with Flyer Paul Holmgren off for hooking, MacKinnon fired a 55-foot shot from the left point that skipped on the ice and got behind goalie Pelle Lindbergh.

"I waited when Mike (Gartner) gave me the puck and then when I shot I think it hit in front of the goalie and got by," MacKinnon said. "I'm really whipped after that game. It's tough sledding, playing four defensemen against those guys."

Bobby Gould provided an essential insurance goal early in the third period, skating down the slot to convert Gaetan Duchesne's pass for his 20th of the season.

It proved necessary when Darryl Sittler beat Jensen with eight seconds remaining, but that score only temporarily halted the crescendo of noise building up from the crowd of 18,022.

Duchesne earlier had been the focal point in a disturbance that further weakened a Washington defense already decimated by injuries to Brian Engblom, Scott Stevens, Timo Blomqvist and Darren Veitch.

Duchesne was knocked unconscious by Flyer Glen Cochrane's elbow behind the Philadelphia net. While he lay on the ice, Dennis Maruk screamed at Cochrane, who promptly knocked Maruk down. Holt came to Maruk's aid and was chased as the third man in the altercation. Cochrane drew 17 minutes in penalties, but his initial offense went unseen by referee Kerry Fraser. Maruk was given a five-minute major.

"The puck was between the goalie and Cochrane, so I go for the puck," Duchesne said. "He swing around and hit me right in the nose with his elbow. For 10 seconds I see nothing and then I see a thousand stars. But the doctor say it's not broken, just blood, so I come back."

Not only did Holt's absence force Coach Bryan Murray to move Houston to the back line, it also meant that Holt will miss Tuesday's game in New Jersey, an automatic suspension for receiving his third game misconduct of the season.

Houston, a defenseman throughout his early career, had not played the position since he entered the NHL with Atlanta in 1975, but he quickly adapted and did not look out of place.

"A big guy like that, he takes up a lot of room," Langway said.

Jensen, winning his second straight game after a month of problems, was outstanding while the Capitals trailed, 2-1. He moved quickly from left to right to foil Brian Propp, then made two point-blank saves on Barber.

Washington's penalty killing was a big factor, as Philadelphia failed to score in five manpower advantages. Two of those penalties came back to back late in the first period with the Flyers ahead, 1-0, as Holt was called for a second cross check before Washington could control the puck while Fraser was signaling an earlier cross check.

Houston made his first appearance on defense while the Capitals were successfully killing off the four minutes. Bob Carpenter and Mike Gartner helped out the four specialists--Duchesne, Gould, Jarvis and Glen Currie--before the time expired with joyous uproar from the majority of the crowd.

Seven seconds after play stopped, there was even more noise, as Maruk evened the score with a centering pass from behind the Flyers net that struck Frank Bathe's skate and caromed behind Lindbergh.