Danny Califf scored in the fifth minute and the Union opened its second season with a 1-0 win over the Dynamo on Saturday night in Houston.
Califf converted a rebound off a shot by Sebastien Le Toux, which had bounced off the crossbar. Le Toux' shot came off a long throw-in hit from Sheanon Williams.
Veteran Colombian goalkeeper Faryd Mondragon stopped three shots on the Union goal in his debut with the team. He was also wearing the armband as the team's captain. Last season, the Union did not have a shutout until Sept. 11, and had just two for the 30-game MLS season.