Right after Yasmani Grandal swung for strike two, a paper airplane came floating from the upper reaches of Chase Field and almost hit him, coming to rest between the batter and catcher Miguel Montero. The next pitch, on an 0-2 count, Grandal airmailed one of his own, a pinch-hit two-run homer that propelled the San Diego Padres to an 8-6 victory Wednesday night and their first three-game sweep in Phoenix.