DC United produced a second-half comeback to extend their home unbeaten streak.
DC United notched a record 20th straight match without loss on home soil after overcoming the Chicago Fire 3-1 in MLS action on Wednesday.
A second-half brace from Jairo Arrieta and Conor Doyle's goal cancelled out David Accam's opener as United continued their unbeaten run in all competitions at Robert F. Kennedy Memorial Stadium.
United - the Eastern Conference leaders by seven points - have not tasted defeat in Washington since June 2014, when they lost 1-0 to Seattle Sounders.
The Fire took a 1-0 lead into the break via Accam, who side-footed the ball past goalkeeper Andrew Dykstra in the 28th minute.
United turned the game on its head after half-time thanks to Arrieta's quick-fire double.
Arrieta headed home the equaliser in the 61st minute and put the home ahead eight minutes later with a cool finish inside the area - his fifth goal of the season.
The result was put beyond doubt with 15 minutes remaining, when Doyle scrambled the ball over Jon Busch from close range.
Vancouver Whitecaps lost ground on the Sounders in the Western Conference after suffering a late 2-1 loss to Montreal Impact.
The Whitecaps looked to have earned a share of the spoils, when Pedro Morales cancelled out Jack McInerney's first-half opener with a 79th-minute penalty.
But Ignacio Piatti had other ideas, finding the back of the net for the CONCACAF Champions League finalists with seven minutes left on the clock in Montreal.
The Whitecaps are three points behind the Sounders, who have two games in hand, while the Impact are second-bottom in the East.
Philadelphia Union easily accounted for Columbus Crew 3-0.
Charles Sapong gave the Union a half-time lead with his 41st-minute opener, and Vincent Nogueira and Sebastien Le Toux got in on the action with goals after the break.