Soony Saad and Dominic Dwyer scored either side of half-time as Sporting survived an early injury to captain Paulo Nagamura and Toni Dovale's 21st-minute red card to claim their first win in six matches.
Sporting entered the match without Graham Zusi and Matt Besler, who are part of the United States' squad for the FIFA World Cup, and the reigning MLS champions lost Nagamura in the third minute to a concussion, before Dovale was sent off in the 21st minute.
The Spanish winger was shown a red card for elbowing Houston's Alex Lopez, who was given a yellow card for his involvement in the scuffle between the two players.
Dwyer could have made it 2-0 in the first minute of the second half at BBVA Compass Stadium but Houston goalkeeper Tyler Deric came out of his box to deny the striker, who was a constant threat to the hosts' defence after the break.
In the 68th minute, Dwyer's header from a corner struck Houston defender AJ Cochrane on the shoulder but the referee pointed to the spot for handball.
