Paul Mulvey last night just what a devastating weapon his 6 feet 4 inches and 215 pounds can be on a hockey rink. Mulvey set a club record with four first-period assists, Mike Gartner collected a hat trick in the first 18 minutes and the Washington Capitals subdued the St. Louis Blues, 7-5, at Capital Centre.

Mulvey crashed into the corners, splattering opponents against the boards. He dug out the puck and repeatedly fed Gartner and Ryan Walter for good shots. And then he stationed himself in front of the net, daring the Blues to move him. Most of the time they couldn't.

For Gartner, it was the second one-period hat trick of the season. He scored three goals in the third period against Quebec in December. Folks have come to expect big things of the first-round draft choice who has collected eight goals in seven games and 27 for the season.

But Mulvey has not been productive recently and in the last eight games, while linemate Gartner was charging full speed ahead, Mulvey had registered only one assist.

In the first period last night, the Mulvey-Walter-Gartner line and goal-tender Wayne Stephenson waged a four-man war against 18 Blues and came out of it with a 4-1 lead. That was remarkable, since at one stage the Blues had a 15-4 edge in shots and trailed, 2-0.

Washington's second shot was deposited in the net by Robert Picard, on a deflection off St. Louis defender Rick Lapointe, after Mulvey had passed out from behind the Blues' net.

The third shot -- St. Louis had 12 by this time -- was netted by Gartner, off Walter's pass, while Mulvey screened goalie Mike Liut.

After Perry Turnbull's second rebound, on the Blues' 16th shot, halved the Washington margin, Gartner scored twice within 20 seconds. Mulvey was the key to the first, regaining possession after Liut blocked his shot, and feeding Gartner in the slot. Then Gartner deflected Paul MacKennon's perfect pass with Mulvey also assisting, for a 4-1 margin.

Bob Sirois, who holds the club record for fastest goals with two in 13 seconds in 1978, hit twice 108 seconds apart in the second period and Washington was laughing 6-1. The first goal was the 200th NHL score for Sirois, who started his career in Philidelphia. The second was his 200th as a Capital.

Before it was over, the laughing was muted, but the Blues never came closer than two goals. Rolf Edberg's rebound, after Picard hit a post made it 7-3 before Wayne Babych and Blair Chapman made the final score respectable.

Stephenson, amazing in the net when the game was close, apparently lost his concentration as the challenge dissipated. He was a behind-the-net wanderer when Babych connected, matching some of shortcomings of Liut, who came here bearing MVP clips and fell on his face -- literally, once, while the Capitals were merely passing the puck in front of him.

Liut lost his balance far from his crease on another occasion and stumbled back to yield Sirois' first goal, then was replaced by Doug Grant after Sirois hit again. Still, Liut said, "It wasn't that bad a game for me" and defiantly added, "There's no way we should lose to the team."

Gartner, who played with Liut at Cincinnati last year, was more charitable, saying, "He's an excellent goal-tender. Everybody has flat moments. Moe (Mulvey) and Walt were standing in front of him so much, I don't think he saw the puck. I know he didn't on my first goal.

"I was getting the puck so much from Moe and Walt, I couldn't do anything but shoot at the net tonight. I could have had a few more, but Grant made some good saves and I shot a couple wide after Moe set me up."

Mulvey was still displaying the intensity in the dressing room that he showed on the ice.

"Walt and Garts were right there to get the puck and it was going our way tonight," Mulvey said. "It's exciting to do that. There was always someone -- Greenie (Rick Green) kept the puck in one time. It takes all five guys on the ice to contribute.

"Walt is a great guy to play with for intensity. You feel bad when you're not intense, not doing things for him. You've got to have it, too.

"It's to say why I haven't been going like this the last couple of games. We had some chances and missed them and I think it made us flatter. But we've turned it around now. Everybody in this room is in a good frame of mind."