Tomas Perez had a one-out single in the first before Russ Ortiz issued consecutive walks to Bobby Abreu and Jim Thome. Ledee followed with a ground ball up the middle to drive in Perez and Abreu for a 2-0 lead.
Chase Utley lined a single into right-center and Todd Pratt had an RBI base hit to put the Phillies ahead, 4-0.
Myers (4-3) allowed two runs in the first inning and six hits in seven frames to win for the fourth time in his last five decisions.
Tim Worrell struck out the side in the ninth for his eighth save in 10 chances.
Ortiz (6-5) was reached for five runs and nine hits in six innings while pitching on his 30th birthday.