D.C. United gave its most elegant performance of the season last night at RFK Stadium, but until defender Diego Sonora scored on a stylish give-and-go midway through the second half, United had 18,234 supporters screeching with anxiety.

Sonora's first goal of the year, assisted by Major League Soccer scoring leader Roy Lassiter, ended 65 minutes of frustration and provided United with a 1-0 victory over the Columbus Crew -- its fifth consecutive victory.

United (8-3, 20 points) increased its Eastern Conference lead to five points over the second-place Crew (7-4), which is 0-10 all-time at RFK Stadium.

Not all was well for United, though. On a late scoring chance, team captain Marco Etcheverry shot meekly at the net and then kicked away the ball in disgust. Referee Tim Weyland gave him a yellow card for an apparent delay of game. That penalty put Etcheverry over the league limit for yellow and red card points and will result in a one-game suspension. He will miss United's home match Thursday against the Miami Fusion. The timing couldn't have been worse for United because four of its players will join the U.S. national team this week for next Sunday's game against Argentina at RFK Stadium; one or two will be permitted to play for United Thursday, and all will miss next Sunday's game against the Crew in Columbus.

Scoring opportunities were plentiful for United last night, but Columbus goalkeeper Mark Dougherty made several excellent stops. Finally, United broke through. Sonora, a right back from Argentina, found space on the right side and pushed a pass to the top of the penalty area. Teammate Richie Williams stepped over the ball to freeze the defense, and Lassiter calmly returned it to the charging Sonora for a crisp 10-yard finish. "It was a nice play," Sonora said. ". . . I just had to finish it up."

United entered the game hoping to maintain the high level of play it showed last week during the second half of a 3-1 victory over the defending champion Chicago Fire. But D.C. would have to do it again without its superb central defenders, Eddie Pope (broken foot) and Carlos Llamosa (sprained knee and ankle). Columbus was without two standouts: forward Brian McBride (fractured cheekbone) and defender Thomas Dooley (pulled groin muscle).

United Coach Thomas Rongen went with the same starting lineup as last week, using three defenders instead of four and giving the on-field organizational duties to Jeff Agoos. The result had only one flaw: United couldn't score.

Etcheverry and Jaime Moreno were dazzling in the middle of the field as Columbus retreated in increasing numbers. But Dougherty made sure the match remained scoreless with four impressive saves.

"We dominated, obviously, from a possession standpoint," said Rongen, whose team had a 22-7 shooting advantage, 12-3 in the second half. "At halftime, the information was very simple: stay patient and continue to play. . . . We created more chances and we really showed a lot of discipline in the second half."

However, Columbus had the next good scoring chance as D.C. goalie Tom Presthus had to make a leg save on Stern John's angled attempt. But United's pressure was too much for the Crew, and Sonora, an offseason acquisition from New York/New Jersey, made his mark.

"We worked so hard to get a goal," Moreno said. "We were a little surprised Columbus was just defending. Usually they attack you all the time. We just kept trying to score and finally we got a goal."

United Notes: Four groups are in serious discussions about purchasing the operating rights to D.C. United, club president and general manager Kevin Payne said, but a deal worth an estimated $25 million to $30 million does not appear close to completion after much progress early this year. Payne would not name the interested parties, but did say one has local ties and another is foreign. According to two sources with knowledge of the situation, the local group continues to be led by Northern Virginia businessman Peter Halpin, who has accompanied Payne to at least two home matches. One source said the foreign interest comes from the banking industry.

Spanish tenor Placido Domingo, head of Washington Opera and a longtime soccer fan, remains interested in purchasing a minority share. . . .

With several defensive injuries, U.S. national team coach Bruce Arena is considering adding Colorado's Marcelo Balboa, a veteran of three World Cups, for the game against Argentina.

CAPTION: Crew's Brian Maisonneuve, left, provides bad trip for Jason Moore. Diego Sonora scored United's goal in 65th minute.