DALLAS (AP) -- Antonio Martinez scored with three minutes to play -- his first goal in Major League Soccer -- giving the Dallas Burn a 1-0 victory over D.C. United on Saturday night.

The loss ended the longshot playoff hopes of the league's defending champions. United, which has won three of the four MLS Cup championships, will miss the playoffs for the first time.

Martinez, a 23-year old rookie from Cal State-Fullerton, entered in the 67th minute. He released a shot that forced a diving save from goalkeeper Tom Presthus, the scored off his own rebound.

D.C. United's Pete Marino had a shot in the 31st minute that forced goalkeeper Matt Jordan into a difficult save. From the left side of the penalty area, Marino cut toward the center and sent a right-footed shot headed for the top right corner of the goal before Jordan stopped it.

United, which played without Marco Etcheverry, Ben Olsen and Bobby Convey, came close on only one occasion in the second half, on a long shot by Antonio Otero in the 76th minute that Jordan stopped.