C. J. Sapong struck the only goal of the game in the fourth minute of stoppage time to earn Sporting Kansas City a well-deserved victory of a lacklustre D.C. United at R.F.K. Stadium.
The 23-year-old American international met Graham Zusi's out-swinging corner kick with a firm header that snook below Jimmy Nielsen and into the net.
The visitors dominated the entire game and United keeper Bill Hamid was forced into a superb save to deny Kei Kamara's bullet header early on.
Bobby Convey provided the Washington defence with problems all game. The former Reading winger twice set up Teal Bunbury, who fired narrowly wide on both occasions.
United offered nothing going forward. Last season's MLS Most Valuable Player and Golden Boot winner Dwayne De Rosario could not muster a single shot on target all game.
City keeper Nielsen had to wait until the 86th minute to make his first and only save from a tame Maicon Santos long-range effort.
After bossing the game, Kansas looked as though they were going to have settle for just one point from their visit to the capital, before Sapong's late intervention.
Robert Summerscales
