Hunter Jumper scored his first MLS goal in the 13th minute Friday and that stood up to give Chicago a 1-0 win over Kansas City.
The Fire won for the third time in four games and moved within two points of Houston for the fifth and final playoff spot in the Eastern Conference.
Kansas City has lost four out of five, but remains in a first-place tie in the East with New York.
Jumper’s goal came on a diving header following a cross by Jalil Anibaba.