An old nemesis was brought down with a vengeance tonight as goaltender Doug Soetaert gave Winnipeg its first shutout victory this season. After nine failures, the Jets finally defeated the Washington Capitals.

The score, 3-0, largely was due to Soetaert's 21 saves in his second National Hockey League shutout. But only 10,649 saw it, having braved weather of 28 below zero.

Using his practice mask for the first time--his game mask was stolen Sunday--Soetaert earned his first shutout since Feb. 6, 1977, when he led the New York Rangers to a 4-0 victory over the New York Islanders in Madison Square Garden.

"People will say it was the mask," said Soetaert. "But let's be realistic. The mask had nothing to do with it. We played the game in textbook fashion. Everybody contributed."

The Jets jumped out to a 2-0 lead in the first period on goals by Morris Lukowich and Dave Babych. Try as they might, the Capitals could not close the margin. They were all but finished when Lucien DeBlois scored for Winnipeg at 9:48 of the third period.

"They played disciplined hockey and skated hard," said Capitals Coach Bryan Murray. "People who put a lot of pressure on us give us a lot of trouble."

If the Capitals had one particularly good scoring opportunity, it came in the second period when Dennis Maruk had a breakaway. But as he approached the Winnipeg net he pushed the puck ahead too far and Soetaert cleared it to the side.

"Another foot and the puck would have been his," said Soetaert.

Lukowich scored what proved to be the winning goal at 7:49 of the first period during a power play. His shot from the faceoff circle to the left of goalie Dave Parro bounced off the shoulder of Washington defenseman Terry Murray.

Seventy seconds later, Babych made it 2-0 when his one man rush ended with Parro fanning at a weak shot.

"When you are a little kid your coach is always saying, 'Get it on the net because anything'll happen,' " Babych said. "I was going to give him (Parro) the big move but I didn't have to. It's not how hard you shoot the puck, but where it goes, you know."

DeBlois insured Winnipeg's victory with a 30-foot shot in the third period after he slipped behind defenseman Jay Johnston. DeBlois was playing his first game after missing 15 with torn ankle ligaments.