Jose Guillermo Ortiz and Luciano Acosta each put through first half goals and DC United hung on to beat Philadelphia 2-1 on Saturday night.
The victory is DC United's first of the season snaps a three match winless streak for DC United against Philadelphia. It is their first victory over the Union since July 2015.
Ortiz found the net first, taking advantage of a Philadelphia turnover in its own zone to give DC United (1-2-1) a 1-0 in the 18th minute. After making a save, Union goalkeeper Andre Blake's pass to Fabinho was mishandled, ricocheting off his head to Lloyd Sam who promptly found Ortiz for the goal.
Acosta added the second goal nine minutes later via penalty kick after the Union were called for a handball in the box.
Philadelphia (0-2-2) got on the board in the 71st minute, when C.J. Sapong scored on a rebound after Alejandro Bedoya's shot was saved by Bill Hamid.