Headley finished 4-for-5 for the NL West-leading Padres, who were coming off a 3-3 homestand that included a series win over the Dodgers. Yorvit Torrealba extended his hitting streak to 15 games by going 3-for-5.
San Diego starter Clayton Richard (9-5) got the victory after laboring through 5 1/3 innings, in which he threw 105 pitches. Richard allowed four runs on 10 hits and three walks, and struck out six.
Dodgers starter Hiroki Kuroda (8-10) allowed five runs -- four earned -- in four innings to take the loss, while Jeff Weaver gave up five runs over the next two frames to put the game further out of reach.
Matt Kemp had a career-high five hits for the Dodgers, who had 14 hits overall, but only two for extra-bases -- Kemp's double and home run. Kemp had three total RBI for Los Angeles, which has lost six in a row to match a season high.