D.C. United stormed to its eighth consecutive victory last night, following the lead of its Bolivian duo to run away from the usually stingy Dallas Burn, 4-1, before 12,093 at a wet RFK Stadium.

Marco Etcheverry, Major League Soccer's assists leader and United's creative force, unveiled his scoring touch for only the second two-goal game of his career here. Bolivian countryman Jaime Moreno added a goal and three assists as United clinched its third straight 20-win season and moved a step closer to winning the Eastern Conference regular season title for the third year in a row.

"It is strange" to score twice, said Etcheverry, who had two goals and 17 assists coming into the game. "I am happy because I haven't had a lot of chances to score goals, but Jaime was pretty much putting the ball in the net for me. These were easy goals."

United's streak is the second longest in club history, one short of last year's perfect midseason run. Only a complete collapse in the final five matches and an unblemished surge by second-place Columbus (16-10, 38 points) could deny United (20-7, 50 points) home-field advantage throughout the playoffs.

United welcomed the return of three starters--goalkeeper Tom Presthus and defenders Carlos Llamosa and Diego Sonora--from injuries that had sidelined them for between three and eight games. Llamosa, who had missed about two months with a strained quadriceps, was replaced at halftime--a move that Coach Thomas Rongen had planned previously in an effort to minimize another injury.

Llamosa survived without further damage, but Presthus, who had sat out three games with a sprained left knee ligament, mildly sprained his right ankle and left in the 77th minute. His status for Friday's game at Tampa Bay is day to day.

Dallas (14-13, 38 points) is the only team to have a winning record against United (6-5), including victories at RFK the previous two years. The Burn had stopped D.C.'s seven-game streak earlier this season with a 3-0 rout at the Cotton Bowl, but United had few weak moments last night.

"I have a very short memory span, but this was maybe our best performance of the year," Rongen said. "It seems like we're getting better every game. We created a lot of chances against this team that normally doesn't give up a lot of goals."

Dallas entered last night second in the league in fewest goals allowed with an average of one per game.

After an even 15 minutes, United established control with Etcheverry injecting himself into every attack.

In the 17th minute, with a free kick from outside the right side of the penalty area, he smacked the ball toward the near post. Goalie Matt Jordan reacted well to the surprise shot and made a diving save, then got back on his feet in time to stop Roy Lassiter's follow-up. However, the ball squirted into the center of the six-yard box for Moreno's deflected finish.

Seven minutes later, Etcheverry got things started again with a long free kick that eventually bounced to Lassiter for a hard shot that Jordan saved. With the ball heading toward the end line, Moreno chased it down and laid it off for Etcheverry to put past Jordan from just a few yards.

Etcheverry was working without his usually reliable support system, namely defensive midfielder Richie Williams, who does the dirty work. Williams sat out with a one-game suspension for receiving a red card in last weekend's victory at Colorado. Also missing last night was another midfielder, Geoff Aunger, who was suspended for one match for an accumulation of yellow cards.

Despite United's efficiency, Dallas cut the deficit in half in the 28th minute when Ecuadoran forward Ariel Graziani scored his fourth goal in four games since being acquired from New England.

With a precarious lead, United wasted no time easing the pressure. Lassiter, Moreno and Etcheverry combined again, this time in the 47th minute. Lassiter caused a commotion deep in the penalty area and got the ball back to Moreno, who crossed to the left-footed Etcheverry for a right-footed poke from 12 yards.

John Maessner added the final goal in the 76th minute, belting in Moreno's cross.

"Neither team played well defensively," Burn Coach Dave Dir said, "but us, by far, way worse. . . . We didn't play with any discipline in the back."

CAPTION: United's Jaime Moreno keeps the ball in play before assisting on goal by Marco Etcheverry.

CAPTION: Dallas goalie Matt Jordan dives to deny Roy Lassiter, left, but moments later United's Jaime Moreno poked in the rebound for game's first goal.