David Villa (left), battling Bobby Boswell for the ball, scored his third goal of the season to avoid a shutout. (Geoff Burke/USA TODAY Sports)

WASHINGTON, D.C. — In his first start of the season, Frederic Brillant was hardly brilliant on one vital play and his mistake cost New York City FC dearly Saturday.

Former Red Bulls midfielder Lloyd Sam took advantage of Brillant’s lapse of play and converted the blunder into a goal for D.C. United, which went on to record a 2-1 win at RFK Stadium.

The loss snapped City’s unbeaten streak at three games (2-0-1) as it fell to 2-2-1 on the season.

NYC FC center back Maxime Chanot sent Brillant a short back pass and the French defender did not notice the speedy Lloyd swooping in on the right side. Sam took the ball away from him and beat goalkeeper Sean Johnson to his right side in the penalty area for his first goal of the season.

Sam played an instrumental role in United’s second goal, although he won’t receive an assist. The English midfielder fired a shot from the right side that Johnson knocked away. Luciano Acosta gathered the rebound and slotted the ball home from six yards for a two-goal lead.

Bill Hamid made a pair of bang-bang saves to keep City off the board in the 82nd minute. First, David Villa powered a shot from outside the box that Hamid knocked away. Jack Harrison drilled the rebound toward the net, which Hamid blocked again.

Those saves were needed as two minutes later Villa tallied his third goal of the season. Harrison floated in a pass to the right side to second-half substitute Tommy McNamara. The West Nyack, N.Y. native found Villa about 12 yards out and the 2016 MLS MVP deposited the ball into the goal past Hamid to cut the deficit in half in the 84th minute.

In the opening half, City’s best chance came in the 44th minute as Maxi Moralez, who at 5-3 and 115 lbs., was the smallest player on the field, managed to get position on his man and headed a right-wing cross by David Villa right to goalkeeper Bill Hamid.

Scoring Summary:
53′: DC – Lloyd Sam 
73′: DC – Luciano Acosta
84′: NYC – David Villa (Assisted by: Thomas McNamara, Jack Harrison)
Disciplinary Summary:
11′: NYC – Alexander Callens (Yellow Card) 
35′: NYC – Ronald Matarrita (Yellow Card) 

New York City FC: Sean Johnson; Ronald Matarrita (80′ Miguel Camargo), Alexander Callens, Maxime Chanot, Frederic Brillant; Maxi Moralez, Andrea Pirlo (75′ Khiry Shelton), Alexander Ring; Rodney Wallace (60′ Thomas McNamara), David Villa (C), Jack Harrison
Substitutions not used: Eirik Johansen, Ethan White, Ben Sweat, Yangel Herrera
D.C. United: Bill Hamid; Taylor Kemp, Bobby Boswell, Steve Birnbaum (C), Nick DeLeon; Jared Jeffrey; Patrick Nyarko (59′ Sean Franklin), Luciano Acosta, Ian Harkes, Lloyd Sam (85′ Lamar Neagle); José Guillermo Ortiz (72′ Sebastien Le Toux)
Substitutions not used: Travis Worra, Kofi Opare, Julian Buescher, Alhaji Kamara
Referee: Drew Fischer
Assistant Referee: Claudiu Badea
Assistant Referee: Jeff Muschik
Fourth Official: Mark Kadlecik