HOUSTON — The third time was decidedly not the charm for the Union.

The Union's third trip to a U.S. Open Cup final in five years ended, as the 2014 and 2015 editions did, with a loss. The Houston Dynamo rode the momentum of a Mauro Manotas first-half brace to a 3-0 win Wednesday night at BBVA Compass Stadium.

It didn't take long for both teams to try their luck on goal, and it actually appeared that Fafa Picault opened the scoring in just the fourth minute, slipping past the Dynamo defense to lift a header over goalkeeper Joe Willis. But it was ruled offside, and less than 30 seconds later, Manotas put in a kneeling header that counted, assisted by Alberth Elis, for the opener.

"It was difficult for us, going from the emotion of thinking we had scored a goal to conceding," Union coach Jim Curtin said.  "I don't think we ever really rebounded from that. Our mentality maybe wasn't there on the night.

"With a team like Houston," he added, "getting a first goal is key for them."

The Union had several hope-giving equalizer chances in a dominating run of first-half possession, including a 19th minute Alejandro Bedoya shot during a lively sequence in front of the Dynamo goal. His shot, however, was blocked by a veteran DaMarcus Beasley playing with the drive and verve of a veteran player knowing this might be his last best chance at a trophy.

Manotas widened the gap to 2-0 in the 25th minute, with Elis setting up the Colombian striker to make a run to the edge of the Union box, where he pinged in a long shot off the post — moving him into the tournament's goal lead with six.

Cory Burke's 62nd minute attempt — only the second shot on goal for the Union all match — was deftly saved by Willis, setting off an up-and-down stage of the game that ended in the worst way possible for the Union.

In the 65th minute, Union defender Auston Trusty, under pressure from a swarming, Elis-led attack, slammed a rebounded Andre Blake save into the net for an own goal to make it 3-0. Trusty, standing with hands on head in front of the Union goal for a painfully long time, exemplified what many a Union fan was feeling in that moment.

Curtin brought Jay Simpson in for Burke in the 68th minute — perhaps later than the Union needed to deliver a sorely-needed scoring punch. Simpson contributed four shots, two of those on goal, but it ended up for naught as the Dynamo finished the night winning their first U.S. Open Cup final.

"We might have outshot them [19-9], and knew we were going to be able to outpossess them,"  Alejandro Bedoya said of the Union's performance. "But we got punished defensively tonight, and it was frustrating."