FRISCO – As it did in their first meeting of the season, FC Dallas let a seemingly sure victory slip away in the waning moments against defending champion Houston on Wednesday night at Pizza Hut Park.

Dwayne De Rosario's goal in the 93rd minute led to a 2-2 draw.

"It takes focus all the way through 90 minutes and the extra time," said FC Dallas interim coach Marco Ferruzzi, who is 1-0-1. "We are still building our mental fitness and toughness and getting through those last couple of minutes.

"We'll get there."

It's the third time this season FC Dallas has allowed a tying score in the final minutes.

During the Texas rivals' first match of the season, on April 6, FC Dallas led most of the match before allowing a goal by Geoff Cameron in the 91st minute for a 3-3 tie.

On Wednesday, Kenny Cooper's sixth goal of the season, in the 35th minute, opened the scoring. Dallas native Drew Moor headed in his first goal of the season in the 69th minute off Andre Rocha's corner kick.

Corey Ashe scored off a service pass from Brian Ching to answer Cooper in the 59th.

Ferruzzi, who won his debut against Real Salt Lake on Saturday, made four lineup changes against the Dynamo. Midfielder Juan Toja and defender Blake Wagner were back in the starting lineup for FC Dallas.

Duilio Davino left in the second half after injuring his right ankle in the first. It was the first time this season FC Dallas' captain did not play a full match.

"The blow came in the 20th minute, and I was playing with a lot of pain," Davino said.

He said X-rays of the injury were negative.

Both teams played with 10 players apiece following the ejections of Rocha for FC Dallas and Eddie Robinson for Houston.