Houston, twice MLS Cup winners and last season's runners-up, will battle the Eastern Conference's top team from the regular season over two legs starting at their own BBVA Compass stadium on Sunday.
Bruin headed Houston ahead from a Brad Davis corner in the 13th minute after his marker, Jalil Anibaba, slipped and left him unattended.
Dynamo should have doubled their lead three minutes before the break when from another corner defender Bobby Boswell was left alone but he headed over from a good position.
Less than a minute into the second half, however, Houston did find the second goal as Ricardo Clark won the ball in midfield and found Calen Carr, who slipped through Bruin to fire home.
Chicago finally came alive in the last 15 minutes with Dynamo keeper Tally Hall doing well to push a Patrick Nyarko effort round the post.
Seven minutes from the end, Brazilian Alex fired home off the inside of the far post but despite some frantic attacks the Fire could not prevent their postseason campaign ending at the first hurdle.
- Sports & Recreation
- Jalil Anibaba