The teams played their regularly scheduled game after beginning the night by finishing a contest that had been suspended May 5. The Nationals won that game 11-10 with a run in the 11th inning.
Washington jumped to a 4-2 lead in the second contest, but Jeff Keppinger tied the game in the sixth with a two-run triple and then scored one out later on a triple by Michael Bourn. Tejada then drove in Bourn with a single to give the Astros a 6-4 advantage.
Berkman hit his 18th homer of the year in the eighth.
Alberto Arias (2-0) got the win by pitching two innings of one-hit relief. He has not given up a run in his last 13 appearances, covering 16 1/3 innings.
Washington starter John Lannan (6-6) took the loss, allowing five runs on 11 hits in five-plus innings. Lannan had been trying for his fifth straight victory.
Copyright 2009 by United Press International.