Kei Kamara scored on a first-half penalty kick for Sporting (11-9-11), which broke a two-match winless streak. Kansas City has 44 points, two ahead of Houston and three ahead of the Crew.
Columbus (11-12-8) lost its third straight and is 0-5-1 in its last six matches.
The own goal came in the 74th minute, when James headed a Kansas City throw-in back and over keeper Will Hesmer.
Kamara put Kansas City up 1-0 in the 15th minute after Chad Marshall brought down C.J. Sapong in the penalty area.