The Orioles trailed by three early in the game, took the lead with a six-run fourth and then surrendered four runs in the fifth to fall behind again.
Baltimore, however, capitalized on a crucial fielding error in the seventh to jump back in front in a battle of playoff-contending teams.
McLouth promptly stole second and went to third on a single by Manny Machado. Chris Davis followed with a ground ball to second, where Eric Sogard misplayed it for an error that brought home McLouth with the tying run.
Machado went to third on the error and put Baltimore in front when he scored on the groundout by Jones. Nick Markakis singled home Davis with the third run of the inning.
Baltimore's big fourth inning was fueled by a two-run homer from Jones and a grand slam by Brian Roberts.
Sogard and Brandon Moss both drove in two runs for the A's, who opened a seven-game road trip by losing their third in a row.