Jorge Dely Valdes is tough to defend and even tougher to convince. Late in the Colorado Rapids' game against D.C. United last night, Dely Valdes looked like he clearly had a goal, but he wanted to make sure. As his shot caromed toward the net with no United players in its path, the Rapids forward boomed the ball the necessary final yard, then ran off, pretending to speak into an imaginary phone.

Seventy-four minutes into the game, Dely Valdes's call had finally been answered, and the Rapids were on their way to a 2-1 victory before 16,387 at RFK Stadium. Dely Valdes had been the most dominant player on the field for most of the night, and now it would be as clear in the game summary as it was on the field.

Earlier, it appeared Dely Valdes' contribution to the game-winning play would be an assist, not a goal. In the 61st minute, Dely Valdes took control of a United corner kick and burst toward midfield, where he passed ahead to Joey DiGiamarino. DiGiamarino sped past Jeff Agoos in the box, then poked a shot past United goalie Tom Presthus.

That goal was the first fruit of the considerable labor of Dely Valdes, who kept United (12-7) on its heels all night. But United responded with an impressive series of headers that culminated with A.J. Wood's goal in the 72nd minute.

That tie didn't last long. Dely Valdes wouldn't allow it.

"In the beginning, a lot of people just talked about [Dely Valdes] in the air," Colorado Coach Glenn Myernick said. "Tonight I think he showed all of us that in tight spots, for a big guy, he has great feet."

United had appeared to grab a 1-0 lead in the 52nd minute when Carey Talley headed a Jason Moore crossing pass off a Rapids defender and into the net. But the goal was waved off when it was ruled that Roy Lassiter was offside.

United Coach Thomas Rongen said he was more irritated with his team's defense than calls like that.

"A disappointing loss, without a doubt," Rongen said. "Our one-on-one defending was not good."

Even so, the game was scoreless at halftime. The Rapids (12-4) had several prime scoring chances early in the game, but a combination of United defense and Colorado's inability to finish prevented any scoring. In the 13th minute, Dely Valdes was closing in on Presthus when Agoos tackled him to ward off a shot. Seven minutes later, Dely Valdes pushed a shot just wide of the far post.

Colorado squandered its best opportunity of the first half with a poor decision. Three minutes in, DiGiamarino found himself wide open in front of Presthus, and apparently not even he could believe it, because he inexplicably tried to pass to Ross Paule. United broke it up, and Presthus didn't even have to face a shot.

"When you get in that position, you have to go for the goal," Myernick said.

Notes: In the 22nd minute, Diego Sonora appeared to be on his way to a prime scoring chance along the right side of the field. But Sonora over-reached for the ball and pulled up limping. He left the game with an apparent groin injury and was replaced by Jason Moore. . . . United defender Eddie Pope sat out his second straight game with a sprained left anterior cruciate ligament. Pope suffered the injury Sunday in San Jose. . . . Carlos Llamosa sat out after picking up a red card in United's game in Columbus, Ohio, Wednesday.