Maicon Santos celebrates with his teammates after scoring one of his two goals against Houston. (Patrick McDermott/GETTY IMAGES)

D.C. United maintained its unbeaten run Saturday night, and at long last, claimed a winning streak.

It’s just two victories in a row, but after faltering 21 times since June 2009 to win consecutive MLS regular season matches, United rebounded from relinquishing two leads and defeated the Houston Dynamo, 3-2, in front of 13,975 at RFK Stadium.

“Losing the lead twice and then coming back shows a lot of spirit,” Coach Ben Olsen said. “There is something to this team. They’ve got a little bit of chutzpah.”

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 4-0-3 since losing the first two games. 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).

The mood wasn’t all cheery, however. Emiliano Dudar, who has provided a commanding presence in central defense, departed late in the first half with a hamstring injury and seems likely to miss a few weeks. Center backs Dejan Jakovic (ankle) and Ethan White (knee) remain sidelined, forcing Olsen to make adjustments for Wednesday’s match at San Jose (6-1-1), the Western Conference leader.

On this night, though, the attack compensated for the defensive issues and goalkeeper Joe Willis’s first blunder since becoming the starter in the second week.

“Last year we don’t come back, we don’t keep fighting and get these goals,” forward Chris Pontius said. “It’s huge.”

Santos scored from six yards in the 11th minute, nodding in Pontius’s cross. But after Dudar exited, United lost its defensive sway. Five minutes into the second half, Bruin was left unmarked for a six-yard volley on Jermaine Taylor’s cross.

United answered four minutes later. From wide on the left, De Rosario drove a curling ball that Pontius attempted to head from close range. Pontius’s movement froze goalkeeper Tally Hall, allowing the ball to skip through the box untouched off the far post. De Rosario, the 2011 MLS MVP and scoring champion, registered his first goal of the year.

The lead lasted five minutes as Willis misplayed Bruin’s low drive from 23 yards. But in the 70th, De Rosario spun, fell, retained possession and cut back before spraying the ball wide to Daniel Woolard for a cross that Santos headed from 11 yards off the hand of the soaring Hall and the underside of the crossbar.

What made the goal so impressive was Santos’s ability to step back and twist his body to generate power behind the perfectly placed header.

“That was a beautiful cross. It’s my job to get my head on it,” Santos said. After beginning the season as a reserve, the Brazilian striker has notched two multi-goal games in a month and raised his team-best total to six.

The front-line alliance between Santos and Pontius, a natural midfielder, has accounted for seven goals and an assist in the past four matches.

“Maicon is a big boy and willing to do the work in terms of holding the ball up and fighting,” Olsen said. “And Chris is very mobile. For now, it’s a good partnership.”

And it helped provide United with rare back-to-back victories.

“The first thing DeRo said [afterward] was, ‘Let’s not let up,’ ” midfielder Danny Cruz said. “And he’s right. Yeah, two in a row is great, but we’re not satisfied.”