The loss would also eliminate FC Dallas from playoff contention.
Chicago would get two first half goals from Mike Magee and Juan Luis Anangono. They would also get a third in the second half from defender Jalil Anibaba.
The hosts would see their playoff chances fade on the night but not before Kenny Cooper scored two second half goals.
Dallas had shaky moments early on in this one, even from the opening whistle. Defenders Matt Hedges and Stephen Keel struggled to clear out a stop by goalkeeper Chris Seitz in the 1st minute, Chicago's Mike Magee nearly pounced on the open chance but Hedges would find a way to clear it out of the penalty box.
Chicago would put Dallas under more pressure in the 17th minute when Michel turned the ball over right outside the penalty box. Anangono quickly gobbled up the mistake and fired a shot just wide of Seitz.
Anangono would get the Fire on the board in the 25th minute off a corner kick by Magee. Anangono wasn't marked very well by Zach Loyd on corner and the Uruguayan Designated Player had no trouble heading it by Seitz.
In the 42nd minute the Fire would add a second goal as Alex took over possession in the Dallas defensive end. He then took a shot outside of the penalty box that hit off Magee's shoulder to go into the goal past Seitz.
The Fire quickly added a third early in the second half. In the 52nd minute, off a Fire corner kick, both Hedges and Jackson failed to clear the ball out past Anibaba, who ripped a shot by Seitz.
Dallas would finally make their breakthrough in the 63rd minute. Ferreira would send a ball into the penalty box to Cooper, who muscled his way onto the ball and was able to put a shot by goalkeeper Sean Johnson.
In the 73rd minute, Dallas would get a penalty kick when Gonzalo Segares pulled down Jackson in the box. Cooper would take the ensuing penalty and fire it by down the middle of the goal by Johnson to pull Dallas within a goal with 15 minutes to play.
The goals would be Coopers seventh and eighth all-time against the Fire.