The Washington Capitals lulled themselves, 12,968 fans and a Canadian television audience to sleep in the third period tonight. The Vancouver Canucks stayed awake, however, and were rewarded with a 5-3 victory.

The Capitals carried a 3-2 lead into the final 20 minutes on goals by Bengt Gustafsson, Dennis Maruk and Tom Rowe. Outshot, 9-2, in the last period, they watched that advantage disappear within the first 95 seconds and eventually they were stung with their sixth loss in eight games.

Jere Gillis scored the winner with 4:07 remaining, by which time Washington had recorded one harmless shot on goal. It was not a nifty effort by the Canucks, but it was enough to prompt them to joyous celebration.

Washington's Yvon Labre lost the puck behind his net to Gillis, who passed out to Stan Smyl. Smyl's shot struck Gillis in the skate and caromed past Washington goalie Gary Inness.

"It hit a skate and came back and went under me," Inness said. "I would have had it if it hadn't changed direction."

"I heard Gordie (Lane) call for the puck and I tried to drill it to him behind the net,' Labre said. " the puck hopped over my stick. I guess I should have frozen it, but if I'd gotten the pass to Gordie we would have been out of trouble."

Don Lever completed the scoring with an empty-net goal, the fourth time in their six defeats the Capitals have been touched for such a coup de grace.

"We're really losing every game by a goal," said Washington Coach Danny Belisle. "Injuries and inexperience are making it tough. We had that goal going into the third and it disappeared so fast. We've got to learn to get over that hump."

Rick Vaive produced that tying score at 1:35 of the third period. Kevin McCarthy sent a cross-ice pass that bounced off the left-wing boards and back to Vaive. He whirled and shot from a sharp angle and the puck struck the stick of Washington defender Paul MacKinnon, deflecting between Innens' legs.

Inness made some remarkable saves to keep it even, foiling a break-away by Ron Sedlbauer and stopping close-in shots by Thomas Gradin and Brent Ashton. Meanwhile, the Capitals were doing absolutely nothing.

"We weren't really playing for a tie, but we would have been happy to get it," Belisle said. "We didn't want to open it up. They weren't really going anywhere until we made those mistakes, although Gary did make a couple of key saves."

Vancouver jumped ahead, 2-0, and eventually maintained its record of winning all the games in which it has scored first. But Gustafson's 50-foot power-play score halved the margin before the first period ended and then Dennis Maruk took over.

With Washington's Mike Gartner in the penalty box, Maruk stole the puck from Vancouver's Kevin McCarthy and beat goalie Glen Hanlon on a breakaway.It was Maruk's eighth goal and the Capitals' first shorthanded score of the season.

Maruk continued to buzz around the Vancouver net and, attracting considerable attention, dropped a pass to unguarded Tom Rowe, who drilled the tie-breaker past Hanlon.

The Caps continued to press for the kill, but both Gustafsson and Rolf Edberg shot wide from close range and the margin was still a precarious one goal when the second period ended.

The Capitals came here with high hopes, since they beat the Canucks in both games at Pacific Coliseum a year ago after failing to win anywhere in Canada during their first four seasons.

Sunday night the Capitals continue their Horse Show-forced travels with a first-ever visit to Edmonton. That figures to be an interesting experience for Gustafsson, who played one game for the Oilers last year and was their property until September, when NHL President John Ziegler reversed his original ruling and awarded the talented young Swede to the Capitals.

"I don't think about it (the earlier situation)," Gustafsson said. "We must win tomorrow, that's all."