Although Bobby Carpenter at 18 is rather young to wear a hat, Capital Centre fans offered a selection for his use last night. Carpenter scored four goals in his first National Hockey League hat trick as the Washington Capitals routed the St. Louis Blues, 9-1, and closed within nine points of Pittsburgh.

Foiled on their first 23 shots by St. Louis goalie Mike Liut, the Capitals scored on three in a row early in the second period. Carpenter then scored three straight goals himself to settle the outcome and added another, his 23rd of the season, with 2:22 left in the game.

Carpenter scored all four goals as a center, moving over from left wing after Bengt Gustafsson pulled a muscle in his rib cage. Lou Franceschetti, recalled from Hershey yesterday, took over on the left side and earned three assists, as did the right wing, Mike Gartner.

"It was a great game, that's all I can say," Carpenter said. "Mike and Louie did an excellent job putting the puck out there and all I had to do was put it in the empty net. My 15-year-old brother could have put three of them in."

Carpenter held up four pucks for the traditional photographic ceremony and a fifth black souvenir was in evidence, around his right eye. Before the four-goal spree started, Carpenter and the Blues' Jim Nill had exchanged punches in a furious fight, begun when Nill used his stick on Carpenter and the young Capital batted it out of his hands.

"Nobody is going to intimidate Bobby Carpenter in this league," said Washington Coach Bryan Murray. "I stated before that once he got a chance to play, he was going to be outstanding. You project a year or two down the road and he'll be a dominant player in this league, a premier left winger or center-ice man, whichever we prefer."

Carpenter said he had no preference, as long as he saw plenty of ice time.

"It doesn't really matter," Carpenter said. "I just happened to get the goals as a center, but who knows, maybe if the game had been tomorrow night I'd have gotten four at left wing. When I came here, I had no idea how many goals I'd get this year. I just wanted to make the team and play."

Murray has never hesitated to play the youngster, although there have been some trying moments as well as enjoyable times like last night.

"He played well early, then he struggled at a point, then played well and struggled," Murray said. "It's easy tonight after those four goals to say he's got it made, but he's still learning. We just want a solid effort and two goals each night are more than enough."

Everybody laughed, but for 22 minutes this game was not a laugher.

The Blues scored first, as Jorgen Pettersson caromed his own rebound off the glove of goalie Dave Parro, who was lying on the ice. Over the next 21 minutes, the Capitals outshot St. Louis, 22-3, but Liut stopped everything.

The spell ended at 2:58 of the second period, as Ryan Walter cut into the slot from the left wing and sent a backhander off Liut's arm into the net. It was Walter's 31st goal and 69th point, matching his best point total in four NHL seasons.

"Liut played excellent the first period, but we're feeling so good, we knew things would break our way," Walter said. "There's no panic any more; we just think it will come."

It came like raindrops, as Lee Norwood sent the next Washington shot into the net on a drive from the left point that deflected off defender Jim Pavese.

Then Dennis Maruk, whose goal-scoring streak ended at eight games, set up Bobby Gould for a hard shot from the slot. It struck Liut's pad and bounced behind him to make it 3-1.

"That was a big goal," Murray said. "Liut seemed to pull up a bit, he had trouble and he was fighting the puck the rest of the way."

Carpenter took over thereafter, making Liut thoroughly miserable. Carpenter set up his first score with an excellent pass from the rear boards to Gartner. Then he hustled out in front and was in position to slip Gartner's rebound behind Liut for his 20th goal of the season.

No. 20 is grounds for a celebration and Carpenter made it one to remember. He scored twice, 25 seconds apart, in the first minute of the third period and the hats flew onto the ice from heads-up fans in the crowd of 8,740.

Carpenter's 21st was one to cherish, as he muscled his way around defenseman Rick Lapointe, who tried to hook him with his stick. Liut left a lot of open net and Carpenter shoved the puck past him for a 5-1 lead.

In other NHL games, the New York Islanders avenged Sunday's record halting loss by beating Pittsburgh 4-2, Denis Potvin, Mike McEwen, and Bryan Trottier giving the home team a 3-0 lead; Keith Ackton's shot bonced into the net off the pads of Quebec goalie Dan Bouchard with 3:27 left for a 4-4 tie that allowed Montreal, loser of only one of its last 18 games to extend its home unbeaten streak to nine; in Calgary, Guy Chouinard had two goals, three assists, Gary McAdam got three goals and Vancouver was routed, 11-4.