D.C. United have lost ground in the race for top spot in the Eastern Conference by suffering a narrow defeat at the hands of Columbus Crew.
Trinidad & Tobago international midfielder Chris Birchall scored the only goal of the game in the opening minute of the second half, latching onto Jairo Arrieta's through ball and firing low past Joe Willis.
It was Birchall's first goal for Columbus - in his third match - since the former Port Vale star completed his move to the States in May.
Columbus keeper Andy Gruenebaum made three excellent saves during the second half to keep his side ahead.