DC United maintained their lead at the top of the MLS Eastern Conference with a 1-0 win over the Philadelphia Union as Luis Silva scored the only goal of the game.
The visitors had the first opportunity of the game when Sebastian Le Toux raided down the flank and crossed for Andrew Wenger, who fired his effort straight at Bill Hamid.
DC took the lead in the 10th minute when the Union failed to clear their lines from a cross into the box and Chris Korb put the ball back into the area, allowing to Silva to head the ball into the bottom corner.
Carlos Valdes kept his side in the game as he made an excellent block on the line to deny Fabian Espindola when he lifted the ball over Rais M'bolhi. The defender then followed it up with another clearance on the goalline to deny Silva from the follow-up effort.
After the break, Philadelphia almost found an equaliser when Raymon Gaddis lifted a cross for Danny Cruz to attack, but Hamid was able to rush out and make a point-blank save to deny the forward.
The Union increased the pressure on the DC goal and Wenger came close when he latched onto a through-ball down the left inside channel and lifted the ball over Hamid, but his effort trickled wide.
Philadelphia upped the ante late in the game and an error from Hamid nearly handed them a leveller when he palmed Maurice Edu's cross into the path of Cruz, but Taylor Kemp did just enough to put the forward off and the ball bobbled safely into the hands of the keeper.