HOUSTON (AP) -- Brad Davis and Will Bruin scored in the first half, Oscar Boniek Garcia and Brian Ching scored in the second and the Houston Dynamo defeated 10-man D.C. United 4-0 Sunday night to extend Houston's unbeaten streak to four games. Brad Davis put the Dynamo (7-5-7, 28 points) ahead 1-0 in the 19th minute on a penalty kick that hit inside the far post. Houston earned the penalty after D.C. United goalkeeper Bill Hamid tripped Macoumba Kandji as he was going for a ball in the box. Hamid was given a red card on the play. United's Branko Boskovic was replaced by backup goalkeeper Joe Willis after Hamid was ejected, and D.C. United (10-6-3, 33 points) played the final 71 minutes a man down. Bruin put Houston up 2-0 in the 37th minute, getting a feed from Luiz Camargo from the right end line to the middle of the box and knocking it in an open net. Garcia made it 3-0 on a header from just outside the left 6-yard box and into the right net off a cross from Andre Hainault from the right sideline. Ching converted another penalty kick in the 89th minute hitting the shot into the right net. Houston earned the penalty kick after Calen Carr was taken down by Danny Cruz in the box. Davis nearly upped the lead to 2-0 in the 21st minute, but his shot from outside the upper box was batted up by Willis, off the bottom of the crossbar and cleared out of the box. Houston continued to pressure D.C. in the 23rd minute, with Bruin's header from 10 yards out in the middle box saved by Willis. D.C. United's Robbie Russell was subbed out in the 40th minute because of plantar fasciitis in his left foot after getting tangled up with Kandji. Chris Kolb replaced Russell. The last time Houston scored four goals in a game was April 29, 2011, against D.C. United in a 4-1 win. D.C. United lost for the second time in three games after a five-game winning streak. Houston outshot D.C. United 19-6, with Chris Pontius having D.C. United's best chances early on, having one shot miss wide right and another saved by Houston goalkeeper Tally Hall.