Atlanta United star Josef Martinez scored in a 10th straight game to set a record in MLS.
New York City's Valentin Castellanos scored a late second-half brace, including the dramatic 93rd-minute winner on Thursday.
Swedish star Zlatan Ibrahimovic criticised the play-off system in MLS.
Wayne Rooney's stay in Washington will prove short-lived after he decided to return to England with Derby - but he wants silverware first.
Wayne Rooney insists he is not ready to retire from playing as he prepares to return to English football with Championship side Derby.
Philadelphia Union midfielder Alejandro Bedoya called on Congress to protect USA's citizens after a spate of gun violence incident