Dallas scored two goals in each half from Matt Hedges, Michael Barrios, Dominique Badji and Reto Ziegler.
Hedges got Dallas on the board early in the first half in the 11th minute off a corner kick from Michael Barrios. The Colombian curled in an out swinging ball that Hedges met for his first goal of the year.
Barrios added the games’ second goal just before the halftime whistle. North Texas SC star Ricardo Pepi put Barrios through to be one-vs-one with the OKC keeper where he fired a shot at the far post.
Dallas scored two more goals in the second half, one from Badji in the 52nd minute from Badji and a final one from Ziegler in stoppage time from the penalty spot.
FC Dallas will likely face rivals Houston Dynamo in the next round at some point next week.