The bottom of the order was the difference in the fourth win in a row for the NL Central leaders. Eighth-place hitter Peter Bourjos singled twice with an RBI, and seventh-place hitter Daniel Descalso walked twice and scored twice.
Wainwright (16-9) prevailed despite allowing three home runs to match his career worst. He left after Starling Marte's two-run shot shaved the lead to 5-4 with none out in the seventh. It was the first time he had allowed more than one homer all season.
Russell Martin and Jordy Mercer homered with the bases empty for the Pirates, who have lost three in a row.
