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.
Selena Gomez drops F-bomb, walks off stage during Jingle Ball performance
Wisconsin business offering 'therapeutic cuddling' forced to close