No, the world did not come to an end last night. It just seemed that way at Capital Centre, where the Pittsburgh Penguins ended the Washington Capitals' season, for all practical purposes, with a humiliating 7-2 defeat.

While the Capitals reached bottom with an uninspiring effort in their biggest game of 1982, disgusted fans responded with raspberries and many among the crowd of 12,144 were heading for the exits with 15 minutes left.

Washington Coach Bryan Murray, disgusted himself, could not help wondering if the fans' penchant for pouncing on Capital mistakes contributed to the disaster.

"When we gave up the first goal, there were catcalls," Murray said. "And when we didn't score on a power play, there were people yelling, 'Nice power play, Caps,' and other things. There was a lot of pressure on these guys and most of them are very young. We had been playing well and still not gaining on Pittsburgh. Mentally, maybe some of these guys are shot."

Mike Bullard and Andre St. Laurent each scored twice for Pittsburgh, which was taking its third straight road game after winning only four of its first 31. The Penguins moved 10 points in front of Washington, which has 12 games remaining in what now seems certain to become the eighth straight season the team has fallen short of the playoffs.

While Murray was offering what amounted to a concession speech, Pittsburgh Coach Eddie Johnston refused to accept a playoff spot, just yet.

"It's an 80-game schedule," Johnston said, "and it's not over yet. I've seen clubs fold at this stage. A few years ago, Toronto was six games behind and made the playoffs by winning six in a row while the Rangers lost six straight."

Reminded that happened in 1961, Johnston said, "Well, I was playing then and I'd like to think it was a few years ago."

It was Murray who was aging last night, wondering how a team that had been playing well could turn so sour, with this debacle following a 7-1 loss in Philadelphia and a mediocre effort in an 8-6 victory over Calgary.

"We wanted to be here, we wanted a chance against Pittsburgh and then we wanted no part of the hockey game," Murray said. "They were on top of us all night and had us shooting from the fringes. I would say it's pretty difficult now, down by 10 points and not being able to beat the team we have to catch."

The Capitals went 10 minutes without a shot in the first period, but still reached the intermission even at 1-1, as a power-play goal by Bobby Carpenter matched a short-handed score by Pittsburgh's George Ferguson during the same penalty.

"Our guys certainly were nervous and uptight," Murray said. "They played like it in the first period. But I thought if we could hold it even for the first period, we'd have a good chance. If anything, we got worse.

"The last time in here we beat them, 8-3, by playing physical against them. Tonight they knocked us down and we got up and complained, but we didn't do anything about it."

St. Laurent, obtained from Los Angeles Feb. 24, and Bullard, who marked his 21st birthday yesterday, gave Pittsburgh a 3-1 lead, but Bengt Gustafsson cut it to 3-2 with a fancy move on which he switched the puck from backhand to forehand and shoved it past goalie Michel Dion.

Dion then made an outstanding save on Dennis Maruk before Rod Schutt deflected Peter Lee's shot at the other end to make it 4-2. That turn of events seemed to take the remaining heart out of the Capitals.

The gap reached three goals before the period ended. A Pittsburgh passout from behind the Washington net was deflected along the side boards to the left of goalie Al Jensen. Ferguson skated swiftly between two Capitals, grabbed the loose puck and fed Bullard for an easy score, the rookie's 32nd.

Paul Gardner and St. Laurent added to the misery in the final period, but a large portion of the crowd was not around to see it.

On a positive note, Carpenter's goal marked the 75th power-play score for Washington, a club record. Gustafsson became the sixth Capital to hit 20 goals, another team mark. It was small consolation.