MLS Cup champions Sporting are four points clear at the top of their conference after a 2-1 win over the Los Angeles Galaxy.
The win was their third straight in the league and extended their unbeaten run in MLS to six matches.
Benny Feilhaber opened the scoring in style in the 11th minute at Sporting Park, curling in a stunning 20-yard free-kick.
In far less impressive fashion, Kansas City doubled their lead just after the hour-mark as Lawrence Olum headed in after a scramble in the area.
Robbie Keane gave his side hope when he beat the offside trap to finish, but the Western Conference's fourth-placed team were unable to find an equaliser.
DC United, who are second to Sporting, can close the gap when they host Chivas USA on Sunday.
Third-placed Toronto dropped points for the fifth time in six league games, needing to come from behind twice to draw 2-2 against the Houston Dynamo.
Will Bruin made it 1-0 to the Dynamo in the 11th minute, capitalising on a poor Bradley Orr back pass before rounding goalkeeper Joseph Bendik and tapping in.
Brazilian Gilberto found room in the area to level just seven minutes later before the Dynamo restored their lead.
Giles Barnes' powerful 25-yard strike found the bottom corner to make it 2-1 and Toronto should have been level just moments later, only for Michael Bradley to strike the post with a penalty.
Toronto would level just before half-time as Luke Moore set up Dominic Oduro to tap in, and that was the end of the scoring.
Elsewhere, MLS leading goalscorer Bradley Wright-Phillips scored a penalty as the New York Red Bulls drew 1-1 against the San Jose Earthquakes.
Bernardo Anor's second-half brace led the Columbus Crew to a 2-1 win over the Montreal Impact and Sebastien Le Toux's late penalty saw the Philadelphia Union draw 1-1 against the Chicago Fire.
Dallas were 2-0 winners over the New England Revolution and Real Salt Lake drew 1-1 against the Vancouver Whitecaps.
