D.C. United failed to keep pace at the top of the Eastern Conference on Sunday, suffering a 4-0 defeat to the Houston Dynamo at BBVA Compass Stadium.
But after 17 minutes of play, it was always going to be difficult for United.
The visitors put together a good first 15 minutes of the contest, but everything unraveled in the 17th when United goalkeeper Bill Hamid was sent off for bringing down Houston's Macoumba Kandji inside the penalty area.
From there, Brad Davis converted the subsequent penalty kick and Will Bruin netted his 10th goal of the season before halftime to make it 2-0.
Houston had plenty of chances to stretch its lead after the break and found the net twice more with Oscar Garcia and Brian Ching providing the goals.
The win keeps a good stretch of results going for the Dynamo, who have earned eight points from their last four games.
United entered the contest having won five of six matches, but falls three points back of leaders Sporting Kansas City in the East.
Hamid's red card was surely the biggest talking point of the match, and substitute goalkeeper Joe Willis was unable to keep out the spot kick from Davis, who tucked his shot just inside the right post.
Davis nearly beat Willis again a few minutes later but the goalkeeper tipped the shot off the crossbar.
Luiz Camargo set up the second goal, which arrived in the 37th minute, when he got to the end line and pulled the ball back for Bruin to finish off from six yards.
Garcia found the net shortly after the hour mark when he headed home a nice right-wing cross from Andre Hainault, who picked out the forward at the back post.
Calen Carr struck the post in the 70th minute for the Dynamo, but Ching capped the scoring in the 89th minute when he converted from the penalty spot after Carr was brought down inside the area.