Late penalty gives Dynamo victory
Clark was awarded the kick when Real Salt Lake keeper Nick Rimando fouled Macoumba Kandji in the penalty area.
Brad Davis of the Dynamo had failed to convert a penalty kick in the 76th minute.
Houston (12-7-9) extended its home unbeaten streak to 22 matches and snapped a four-match winless streak overall.
The Dynamo are 8-0-1 in home games against Real Salt Lake (14-11-4), which nearly secured its first ever win in Texas, but Houston goalie Tally Hall saved Nat Borcher's header attempt. Real Salt Lake is 0-18-3 against FC Dallas and Houston on the road.
Both teams played without several players because of international callups, suspension or illness. Dynamo head coach Dominic Kinnear was given a red card and was ejected in the 90th minute.