D.C. United tops Houston Dynamo for first MLS win streak in nearly three years Maicon Santos capped a two-goal performance with a 70th-minute header, the fourth strike in a 20-minute stretch that featured a rush of opportunities and defensive follies on the rain-slick field. Dwayne De Rosario also scored for United, which is on a 4-0-3 surge since losing the first two games of the campaign. Will Bruin had two goals for the Dynamo (2-2-2). Since defeating Chicago and New York in a nine-day span almost three years ago, United had gone 0-10-11 when presented with an opportunity to follow one victory with another. With the latest result, United retained second place in the Eastern Conference behind idle Kansas City (7-1-0, 21 points). Coach Ben Olsen kept the same starting lineup that thumped the third-place New York Red Bulls, 4-1, six days earlier. The Dynamo arrived with four victories and a draw in its past five meetings with United, averaging three goals per game in that span. On this night, though, United seized the early initiative and created two high-quality chances inside seven minutes. Houston goalkeeper Tally Hall knocked down Nick DeLeon's powerful one-timer from 17 yards and a sharp combination initiated by DeLeon on the left side was left unfulfilled when Santos missed the far corner. Four minutes later, Santos was on target. Chris Pontius ran onto Brandon McDonald's long ball out of the back and touched it past the adventuresome Hall on the side edge of the box. Without an angle to shoot, Pontius surveyed his options before crossing to Santos, who ducked inside Andre Hainault for a six-yard header. United sustained its energy and bite but not possession, and despite a few harried moments in heavy rain, Joe Willis wasn't tested the remainder of the half. There was a major setback, though, just before the break: Emiliano Dudar, who has provided a commanding presence in central defense, departed with an apparent hamstring injury. With the other two center backs sidelined with injuries, Olsen inserted midfielder Marcelo Saragosa, dropped Perry Kitchen to right back and moved Robbie Russell into Dudar's slot. Houston took advantage five minutes into the second half. Jermaine Taylor beat Danny Cruz on the left flank and crossed to the unmarked Bruin for a six-yard volley. United answered four minutes later when De Rosario drove a curling ball that kissed in off the far post. Pontius had attempted to head it from close range, freezing Hall, but apparently didn't make contact. The lead lasted five minutes as Willis misplayed Bruin's low drive from 23 yards. But in the 70th, De Rosario fell, spun and cut back before spraying the ball wide to Daniel Woolard for a cross that Santos headed from 11 yards over the leaping Hall. Hall prevented further damage with a superb save on De Rosario deep in the box. United notes: After playing five of six at home, United will travel to San Jose (6-1-1) on Wednesday, Toronto next Saturday and Houston for the debut of the Dynamo's new stadium May 12. . . . Defender Dejan Jakovic (ankle) wasn't available for the third consecutive match.