Headley hit a solo home run in the bottom of the eighth inning that punctuated the Padres' 9-5 win, a ball that carried just past the porch area in right field.
Headley, a switch-hitter, has hit 18 of his 47 career home runs at Petco Park, though most haven't been pulled from the left-hand side of the batters' box.
"I think that's only the second one I've hit out there," Headley said Saturday. "I bet in my five years here, I've seen less than 15 hit there and maybe less than 10."
While there's a porch area in right field that sits just beyond the 322-mark, it's not an area where a lot of hitters get home runs. Most at spacious Petco Park, are hit to left field (336 feet down the line) as well as left-center field or center field.
So why haven't there been more home runs down the right-field line?
"I can't think of many," said Padres manager Bud Black. "Maybe you look at a right-handed pitcher and what they're trying to do to left-handed hitters ... especially in this ballpark. The sinker comes into play here and maybe they try to throw pitches that might get a ball down the line."
Off the top of his head, Black said he can remember more right-handed hitters hitting a ball into the porch area in right field that jettisons out from the wall. Marcus Giles hit one there. And so did Yorvit Torrealba and, more recently, Buster Posey of the Giants.
Even former Padres All-Star first baseman Adrian Gonzalez, a left-handed hitter, hit more of his balls to left field instead of pulling it to right field.