PITTSBURGH (AP) – Michael Chavis drove in the go-ahead run in the seventh inning as the Pittsburgh Pirates came from behind to beat the Washington Nationals 5-3 and take the four-game series.Chavis’ single to left field against Nationals reliever Steve Cishek (0-1) scored Josh VanMeter to put the Pirates in the lead and complete the comeback from down 3-0. Pittsburgh also came back from three runs down to beat Washington in the first game of the series on Thursday.