The forwards combined on a pair of goals as United secured the victory without the services of suspended striker Eddie Johnson.
With designated player Eddie Johnson suspended, United improved to 5-3-3 as forwards Fabian Espindola and Chris Rolfe combined on a pair of goals in a 2-0 win over the Houston Dynamo (5-6-2) at RFK Stadium.
United took the lead in the 28th minute. Espindola stripped Dynamo defender Jermaine Taylor near midfield before finding Rolfe, who converged on the box, turned around David Horst with a cheeky cut and fired home a low shot. It was the third goal for Rolfe following an early-season trade from Chicago, and Espindola's fifth assist of the campaign.
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Rolfe nearly doubled the lead in the 61st minute, when his volley from the top of the box rang the crossbar. But the miss only delayed the inevitable.
This time it was Rolfe playing provider, looping a 63rd-minute pass to the left flank that Espindola casually brought down. The Argentine then eluded Horst with some clever footwork and slotted his shot inside the far post for his fifth goal of the year.
Already down World Cup camp call-ups Brad Davis (USA) and Boniek Garcia (Honduras), as well as the injured Ricardo Clark (concussion), Houston lost striker Mark Sherrod to an early injury and midfielder Brian Ownby to a late red card.