Philadelphia Union have crept into a playoff spot in the MLS Eastern Conference with a 1-0 win over Sporting Kansas City.
The result takes the Zoros two points clear of sixth-placed New England Revolution, although they have played one game more than the Massachusetts outfit.
John Hackworth's men had gone 346 minutes without scoring a goal before Conor Casey struck against the run of play in the 36th minute, which ultimately decided the game at Sporting Park.
It was the good work of Danny Cruz that helped set up the winner, as he glided past Ike Opara before clipping a ball into the box that was only half dealt with by Aurelien Collin.
The 32-year-old striker then appeared to handle the ball, setting up Michael Farfan to fire at Jimmy Nielsen, but his shot was well saved.
However, the rebound fell to Casey, who showed no mercy in firing into the net and wheeling away amid a chorus of boos.
Nielsen denied Farfan for a second time in the 63rd minute, this time with an outstretched foot, after the midfielder got himself on the end of a Sheanon Williams cross.
The hosts dominated possession and had plenty of efforts on goal, but they were unable to break down a resolute Union side, who defended in numbers to eke out three points on the road.
The Wizards could have gone level on points with leaders New York Red Bulls had they won, but instead they remain in second place - three points ahead of Montreal Impact.
