Garcia (2-2) made his sixth start for the Orioles, the seventh major league team for which he has played in a 15-year career. He struck out six and did not walk a batter in a 113-pitch effort that brought the Orioles their second straight win.
Washington managed only one major threat, putting runners on first and second with none away in the second before Garcia retired the next three batters.
Jim Johnson retired the side in order in the ninth to collect his 17th save.
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