Both teams were playing their third match in a span of eight days and it showed, though FC Dallas seemed the worse for the wear, especially in the first half.
Houston (5-10-11, 26 points) won for just the second time since May 22 and is in 12th place in the 13-team Western Conference, with five teams to climb over -- including FC Dallas -- to get above the playoff line.
FC Dallas (6-11-9, 27 points), fell to 11th place in the Western Conference with eight matches to play, and is now 2-4-3 in its past nine matches, with both of its wins in that span coming against expansion Austin FC.
The Dynamo jumped in front in the fifth minute when Griffin Dorsey scored the easiest of goals after a pass from Fafa Picault rolled all the way across the box to the far post. From there, Dorsey just tapped the ball past Dallas keeper Phelipe Megiolaro, who had no chance to make a save.
Picault was rewarded for his hard work 15 minutes later, running with determination to the near post for an assist from Dorsey and scoring into the bottom left corner with his right foot from very close range. The play began with a pass deep into the box from Darwin Quintero.
Jader Obrian spoiled the shutout for Houston when he got FC Dallas on the board in the 86th minute, scoring from a severe angle after an assist by Jesus Ferreira. He then scored again four minutes into stoppage time after an assist on a corner kick from Eddie Munjoma to make the final moments tense for the Dynamo.
The teams played to draws in both their other meetings this season, 1-1 in Dallas in May and 2-2 in Houston in August.