Myers (4-2) won for only the fourth time in 11 starts despite coming into the game with a 2.86 ERA. He gave up two runs on three hits with six strikeouts and only two walks while lowering his ERA to 2.80.
Aaron Rowand went 2-for-3 scored a run for the Phillies, who won their third straight game. Before this winning streak, Philadelphia had lost nine of its last 11 games.
Marlon Byrd hit a two-run homer for the Nationals.
Tony Armas (5-3) came into the game 5-0 over his last eight outings, but suffered the loss after allowing four runs on five hits with a pair of walks and five strikeouts in 6 1/3 innings.
Armas didn't allow a hit until the fourth, but gave up three runs in that inning.