The St. Louis Blues blew a sour note for the beginning of a Washington Capital 10-day road trip last night, defeating the home team, 3-2, on a goal by Rick Lapointe with 2:27 left to play and the solid goaltending of Mike Liut, who was voted No. 1 star of the game after making 28 saves.

As a crowd of 14,179 at Capital Centre looked on in dismay, Lapointe skated in from the red line on a two-on-one break and fired the puck from about eight feet out. Cap goalie Mike Palmateer lunged for the puck as it soared toward the upper left corner of the net, and the puck glanced off him and flew in.

"I got a solid piece of it with my shoulder," said Palmateer, "but it popped into the goal."

As he passed the red line with the puck, Lapointe looked right, as if contemplating pass to Blair Chapman, with Cap. Pat Ribble the last line of defense between the two Blues and Palmateer.

It appeared to some that Ribble, who acknowledged responsibility for the first St. Louis goal, had misplayed the game-winner also.

But Lapointe disagreed. "He played it pretty well perfect," said Lapointe, a defensive defenseman who scored his first goal this season and only his 27th in his six National Hockey League seasons.

"If he comes over on me, I'd slide it over to Chapman and he'd have the whole net."

The loss brought the Caps' season record to 3-3-1, but it was especially painful because it denied them the momentum they would have liked to begin the road trip.

"I'm not going to camouflage it," said Cap Coach Gary Green. "We just weren't up to full intensity tonight. I'm not happy with anyone's performance."

The Caps begin their road trip with a rematch against the Blues tonight in St. Louis (WDCA-TV-20 at 9 p.m.)

"We've certainly got something to sleep on," said Green. "They're obviously going to be confident in their own house. But our club has a lot of character, and I have every confidence in us."

The Caps were first to enter the scoring column when Bengt Gustafsson fired the puck past Liut after only 2:02 had expired in the first period with Washington's Wes Jarvis sitting in the penalty box on an interference call. Palmateer made a save and slapped a St. Louis shot toward the opposite goal. As the puck neared the blueline, St. Louis defenseman Craig Norwich tried to knock it down and resume the attack.

But the puck deflected off his glove, Gustafsson broke behind him and took it, then skated in all alone from the right wing and scored.

The Caps had not lost a game this season in which they scored the first goal, and they appeared sharp early on. But a costly mistake by Ribble five minutes later appeared to change the tenor of the game.

On that play Blues right wing Tony Currie, with assists from Jorgen Pettersson and Bryan Maxwell, faked out two Cap defenders and scored on a backhand with Palmateer laying on his back after coming out to cut down the angle. The last line of defense, Ribble attempted to take the puck instead of the player. He failed.

"That first goal was completely my fault," said Ribble. "I know I didn't play a very good game. The puck didn't bounce right for anybody on our team."

The Caps outshot the Blues, 30-25, with the two goalies named the best players on the ice. In the second period the teams traded goals, St. Louis scoring on a shot by Perry Turnbull at 4:29 and Washington answering when Alan Hangsleben took a nifty pass in the slot from Guy Charron and beat Liut with a backhand.

At that point the Caps were aggressive on offense, but Liut was brilliant. The momentum turned minutes after Washington's tying goal when Liut stopped two Cap shots within seconds of each other on a two-on-one breakaway.

Liut, who won a league-high 32 games last season, is 5-1 this campaign. What gained his coach's praise last night was his ability to cover the rebounds.

"He played very well," said Red Berenson, whose team had not won a game here since 1978. "He made the initial stop, stayed on his feet and made the stop on the rebound, which is more important."