Exasperated groans grew from Minnesota United fans during the second half of the Loons’ match against FC Dallas on a steamy Friday night at TCF Bank Stadium.

As the Loons threatened Dallas’ goal — only to fail in connecting pivotal passes and routinely push shots just off target — the sellout crowd of 22,345 showed how their anticipation turned to frustration at each juncture.

When those chances stacked up in the open end of the stadium, coach Adrian Heath often whipped around to the other end of the stadium and furrowed his brow to either look to the heavens for answers or toward the high video replay board to see if he could piece together reasons himself.

“I think maybe since I’ve been here, most chances created in a game, most corners, had some good opportunities, and the longer it goes, you always leave yourselves susceptible,” Heath said. “Another poor goal to concede.”

The bottom line is the Loons had 15 shots and 13 corner kicks but only five shots on target as Dallas made one of four shots count for a 1-0 win.

“It was one of those days where the ball didn’t seem to want to go in,” United striker Christian Ramirez said. “I personally had one that passed barely by the post. (Jesse) Gonzalez makes a great save on Brent (Kallman) somehow. Ibson’s barely misses. It was one of those days where it didn’t seem like we deserved to lose.”

Dallas was propelled by a second-half goal. Santiago Mosquera’s corner kick went to the head of Simon Lamah in the 59th minute. Lamah got higher than his mark, Tyrone Mears, and directed the ball past outstretched goalkeeper Bobby Shuttleworth.

“Somebody not picking their man up,” Heath said. “I keep going over it. I keep talking about it. Unfortunately at the moment, we’re not learning the lesson.”

After an ugly 3-2 loss to low-rung Colorado last week, which included a header winner off a set piece, Minnesota’s veteran players called a team meeting and spoke up to help stem the losing slide. It didn’t pay immediate dividends. The Loons (5-10-1) suffered their third straight defeat and have only one win in their past seven MLS games, while Dallas (9-2-5) maintained its spot near the top of the Western Conference.

Minnesota and Dallas each were without key offensive playmakers — and it showed. Sans sparkplug midfielder Miguel Ibarra, out with a red-card suspension, United often didn’t have a lot of attacking options in the first half. Same for Dallas without Mauro Diaz, who reportedly is leaving Texas on a transfer to the Middle East.

“(Miguel’s) energy is infectious, people feed off that,” Heath said. “We missed him (Friday) evening.”

The Loons started with a 3-5-2 formation, a deviation from their traditional 4-2-3-1, and shifted to other looks at other times as the dynamic of the game moved. Down a goal, they swapped rookies, bringing on forward Mason Toye for center back Wyatt Omsberg, but it didn’t provide the breakthrough.

Like in Colorado, failing to capitalize on first-half opportunities came back to bite the Loons. They had eight corner kicks in the opening 45 minutes, a jump from the 5.9 corners averaged over the first 15 games.