For the 10th time in their seven-year history, the Washington Capitals have been strapped with a double-figure winless streak. The current slide stretched to 10 games last night as the Pittsburgh Penguins leapfrogged past the Capitals into 15th place with a 7-5 victory at Capital Centre.

The result amounted to a disaster for Washington, which has not won a game since Feb. 1. The Penguins have been pigeons for the Capitals in the past; they had won only five road games all season and had been able to conquer only last-place Winnipeg on foreign ice in 1981.

Last night, however, the Penguins swept past the retreating Washington defensemen, escaped the half-hearted checks thrown their way and built a 7-3 lead by the 12th minute of the second period. Then, as usual with the pressure off, the Capitals mounted a futile comeback.

Coach Gary Green, an unfamiliar choking note to his voice, tried hard to convince skeptics that the sun was still shining: "We know we've got our backs to the wall and we have to help ourselves. But it's not as if all is lost. You just go right back at it tomorrow."

The problem is that tomorrow finds the Capitals in St. Louis to play the first-place Blues. If they cannot beat Pittsburgh on home ice, whom can they beat?

There was a modicum of good news for Capital watchers last night. Goalie Mike Palmateer officially earned his seveth assist of the season, an NHL record for goaltenders. That broke the mark established by Gilles Meloche in 1974-75 with the California Seals.

As far as work in goal was concerned, Palmateer looked shaky, after stopping 43 shots in Chicago Wednesday night to earn the Capitals an undeserved 2-2 tie.

Mike Gartner and Jean Pronovost each scored twice for the Capitals, Pronovost hitting the 20-goal mark for the 12th straight season. He was unimpressed.

"Seven-five for them; that's all that matters," Pronovost said. "That was a key game."

Bengt Gustafsson and Tim Tookey each had three assists, giving Tookey five in two games since being recalled from Hershey Monday. Mark Lofthouse, another Monday recall, scored his first goal.

A holding penalty to Jim McTaggart set up the fourth Pittsburgh goal, as McTaggart wound up in a shouting match with Rod Schutt and Washington received an additional minor because he did not proceed directly to the penalty box. A similar faux pas by Paul Mulvey, now in Hershey, opened the door for Quebec in the 11-7 fiasco Sunday. This time Rick Kehoe capitalized on the two-man advantage to record his 44th goal.

"Tags (McTaggart) got a stick in the neck and I was yelling at him to go," said Green, who wound up standing on the bench screaming in frustration at referee Andy Van Hellemond. "I knew Andy didn't see it, because he was delivering the penalty. This is two games now we've been put behind the eight ball with a double minor."

"That was a dive (by Pat Hughes)," McTaggart said of the original penalty. "He was a little by me and I pushed him into the boards and he put on the act. Then Schutt was waving the stick at me."

A power-play goal by Pronovost reduced the deficit to 4-3 before Pittsburgh scored three times in 6 1/2 minutes. The one that made it 7-3 was scored shorthanded by Randy Carlyle, the 12th such goal yielded by the Capitals this season.

Gartner and Pronovost hit in the third period and there was still hope for a miracle among the 11,546 fans when Hughes was caught hooking at 14:26. Coincidental high sticking penalties to Gartner and Carlyle removed Washington's chief scoring threat, however, and the Capitals proved ineffectual, despite two earlier extraman goals and Pittsburgh's status as the worst in the league at killing penalties.

"I still think had we not received that penalty in front to Gartner, the way that power-play unit was going they might have gotten a goal and pulled out something," Green said.

Coaches have a way with words. Witness the comment of Pittsburgh's Eddie Johnston: "The importance of this game was very important."

In other games, the Canadiens shut out the Rockies, 6-0, in Montreal to run their unbeaten streak to 11 games; the Bruins beat the North Stars, 5-1, in Boston in a brawl-filled game. Twelve players were ejected and an NHL record for most penalty minutes (392) established.