Tommy Rowe scored four goals and he and linemate Dennis Maruk each had six points as the Washington Capitals survived a sloppy spell in the third period and beat the St. Louis Blues, 7-5, last night at Capital Centre.

The Capitals played 40 minutes of superb hockey, cruising to a 6-2 lead while breaking several team records.

Then they spent 12 minutes congratulating themselves and almost ruined the whole evening. It took a goal by Maruk at 15:33 of the third period to put the Capitals back in control as they held on to win in front of 11,366.

"We just got caught with five guys not reacting in our own end," Coach Danny Belisle said of the third-period letdown. "St. Louis didn't quit, kept digging and trying. They've been playing good hockey."

The story of this game was the recently created line of Rowe, Maruk and Rolf Edberg. Rowe had two assists in addition to his four goals, Maruk two goals and four assists and Edberg four assists.

"That one line just killed us," said Blue Coach Barclay Plager. "We couldn't stop them all night. When we finally got going they turned around and scored on us again."

The Rowe-Maruk-Edberg line was created by Belisle when winger Greg Polis was injured more than a week ago.

The new line played as if it had been together for years. Edberg and Maruk set up Rowe three straight times in the first period, giving the 22-year-old American his first hat trick in the NHL.

It was the first time a Capital had scored three consecutive goals and the first opening-period hat trick by a Cap.

It looked as if the Caps would win their 21st game of the year with ease early in the second period when Rowe set up Gord Lane for his first goal since last March at 7:59.

But then the Blues, who, like the Caps, brought a four-game unbeaten streak into the game, began skating and checking, especially in the Caps' end.

Two quick goals by defenseman Jack Brownschilde made it 4-2 before Maruk's line swung into action again. First it was Rowe, equaling the club record of four goals in a game (set by Stan Gilbertson in April, 1975) with a tip-in off a perfect pass from Edberg at 17:21.

Then Maruk knocked down a St. Louis clearing pass and blasted a 40-foot shot past goalie Ed Staniowski at 18:37 and it was 6-2.

"Dennis and Roif make things so easy," Rowe said modestly. "They just keep digging and digging and all I have to do is go look for an open spot and wait for the puck. Tonight it was there all the time. Every goal was perfect, just perfect."

Before the Caps could celebrate the bevy of records they set on the night, they had to hold off the Blues' third-period charge.

Back-to-back goals by Rick Sutter -- giving him 36 for the season -- made the game close at 6-4, then Garry Unger's 27th goal at 11:36 made it too close as far as the Caps were concerned.

"When you're that far ahead sometimes you start thinking, 'Gee, we're just going to score and score,' and then you let down just a little," Maruk said. "We can't afford to do that, we have to keep digging."

It was Rowe's digging in the corner that set up the clinching goal. He dug the puck out of the right corner and fed Maruk, flashing in on Staniowski. Maruk,deked right, Staniowski went right and Maruk shot left for his 27th goal.That gave both Maruk and Rowe six points for the night, tying a club record.

"Heck, I was wide open," Maruk said. "Right place at the right time, you know."

Maruk's line was in the right place at the right time all night as the Caps. trying desperately to catch Pittsburgh for the final playoff spot, raised their season point total to 53.

Maruk's six points gave him 77 and his first assist broke Guy Charron's club record of 46 assists as he raised his total to 50.

"It was just a great night for all of us," said Rowe of the 16 points scored by the trio.

The Caps move to Detroit today for a 4:05 p.m. game.