Brian Gutiérrez scored in the 87th minute Saturday night, Hugo Cuypers and Philip Zinckernagel also scored and the Fire beat St. Louis City 3-2 at SeatGeek Stadium to extend their unbeaten streak to five games.
Gutiérrez rolled a shot from well outside the area inside the right post to cap the scoring.
Andrew Gutman, on the counterattack, ran onto a long ball played ahead by Gutiérrez and bent a low cross from the left side to Cuypers for a first-touch finish from near the penalty spot to open the scoring in the 16th minute.
Cuypers has 15 goals this season and became the fourth player in club history to accomplish the feat and the first since Nemanja Nikolić in 2018.
Tomas Ostrak scored his first goal of the season to make it 1-1 in the 47th minute. After a failed clearance attempt, Ostrak flicked a left-footer from the center of the area inside the left post.
Marcel Hartel gave St. Louis (5-15-6) a 2-1 lead in the 59th minute when he stopped a cross played from the right side of the area by Ostrak and blasted a shot into the top-net from near the left corner of the 6-yard box.
Zinckernagel, on the counter-attack, outraced a defender to the edge of the penalty area, cutback to evade another defender and then rolled in a shot to make it 2-2 in the 67th.
Chris Brady had two saves for Chicago (11-9-6).
The opening kickoff, which had originally been set for 7:30 p.m. local time, was delayed about 90 minutes due to inclement weather in the area.