Kansas City missed the chance to go top of the MLS Eastern Conference as they slipped to a 1-0 defeat at home to Chicago.
Marco Pappa scored the only goal after 58 minutes as the Fire pulled to within two points of their opponents.
Third-placed Kansas City would have gone above leaders DC United and the second-placed New York Red Bulls with a win.
"We had 27 shots. It's not like what we're trying to do didn't happen. We just didn't stick it in the back of the net," Kansas City coach Peter Vermes said.
"It was pretty even in the first half. I thought we were all over them in the second half. We made a mistake on the run-out play - we had too many guys forward and nobody back, and they executed it very well."