Houston christens their new BBVA Compass Stadium along with D.C. United on Saturday. The opener draws a sellout crowd of 22,039, nearly all of them clad in orange. (Pat Sullivan/Associated Press)

On a sheet of paper taped to a pillar in D.C. United’s locker room, a clear message greeted the players before Saturday’s MLS match against the Houston Dynamo: “Let’s Spoil This Party!”

United’s party-crashing efforts, however, were undermined by the Texas heat, injuries to two starters and a mighty strike by Brad Davis midway through the second half of a 1-0 defeat at the formal opening of orange-splashed BBVA Compass Stadium.

Already missing four regulars, United (5-4-3) lost defensive midfielder Perry Kitchen to a knee injury in the first half and forward Chris Pontius to a gluteus muscle ailment shortly after halftime. The injuries, combined with United’s first match of the season in warm conditions and Houston’s emotional lift from the sellout crowd of 22,039, resulted in only the second loss in the past 10 matches.

“It was always going to be a tough task here,” United Coach Ben Olsen said. “When you saw this on the calendar, you’re opening up Houston’s stadium. . . . Guys dug in and did what they could, but injuries and the heat were a bit too much to overcome.”

Kitchen departed in the 28th minute after landing awkwardly. He will be evaluated upon United’s return to Washington, but seems certain to miss both matches this coming week.

“We have to evaluate it and see what the doctors say,” he said. “We’ll see. I am definitely nervous about it.”

Olsen was worried, saying, “It doesn’t look great. It’s not going to be a five-to-seven-day injury. Hopefully it will be something minor.”

Pontius, United’s second-leading scorer with five goals, aggravated an injury that has bothered him for weeks. He, too, will undergo testing at home.

The opening of the new stadium attracted MLS Commissioner Don Garber, Houston Mayor Annise Parker; West Virginia Athletic Director Oliver Luck, the Dynamo’s former president; Luck’s son, Andrew, the No. 1 pick in the NFL draft; and boxing legend Oscar de la Hoya, a Dynamo minority investor.

United goalkeepers coach Pat Onstad, a former Dynamo star, participated in the pregame ceremony, and United’s Dwayne De Rosario and Danny Cruz, ex-Houston players, received warm ovations during introductions.

On an otherwise upbeat day, there was one notable flaw: the field width. Despite ample space for broader dimensions, the Dynamo (3-3-2) chose 70 yards — barely acceptable on the pro level. For tactical reasons, Houston maintained the size offered at the previous venue, Robertson Stadium.

Both sides labored to create opportunities in the first half, but as the match unfolded, the Dynamo gained greater possession and thumped dangerous balls into the box. Bobby Boswell’s one-timer missed the open near corner and Je-Vaughn Watson’s 16-yarder streaked over the crossbar just before halftime.

A minute after the break, United goalkeeper Bill Hamid, in his second consecutive start, made a leaping save on Adam Moffat’s rasping drive from 25 yards.

United’s first quality chance came in the 57th minute when Maicon Santos’s angled bid skidded wide of the distant corner.

Houston’s breakthrough came 10 minutes later. Davis, runner-up to De Rosario in MVP voting last year, was given time and space to turn and then crack a left-footer from 28 yards to the upper right corner.

“He hit it well,” Hamid said. “I’m lucky I got my fingertips to it.”

The Dynamo followed with waves of opportunities, but Hamid’s reaction saves and Houston’s wayward touches left the outcome in the balance. United had little left to offer until De Rosario’s free kick connected with Daniel Woolard in stoppage time for a header covered by Tally Hall.

“You saw fatigue come in,” De Rosario said. “I don’t think we did a whole lot going forward.”

The lack of energy surprised Olsen.

Kitchen’s injury “coincided with a real sense of fatigue throughout our team, which I didn’t think was going to be an issue,” he said. “The guys were fresh but the heat hit us pretty hard.”

United notes: Center back Ethan White, who hasn’t played this season following knee surgery, made the game-day roster for the first time. Defenders Emiliano Dudar (hamstring) and Dejan Jakovic (ankle), as well as midfielders Nick DeLeon (hamstring) and Marcelo Saragosa (calf) remained out. . . .

United will play the next three matches at RFK Stadium: Wednesday vs. Colorado, Saturday vs. Toronto and May 26 vs. New England.