Lionard Pajoy scored the only goal as DC United won 1-0 away to Philadelphia Union to keep the pressure on the leading clubs in the MLS Eastern Conference on Wednesday.
Pajoy scored after 67 minutes as United moved up two places to fourth in the standings.
Defeat leaves Philadelphia in the bottom two of the table.
Sporting Kansas City went four points clear at the top of the Conference on Wednesday with a 2-0 win away win over New York Red Bulls.
[table id=6 /]
[table id=7 /]