Adam Dunn belted a two-run homer and five others drove in a run for the Washington Nationals in Wednesday’s 7-5 win over the Pittsburgh Pirates.

Roger Bernadina had three hits and an RBI to help Washington take the first two games of the series.

The Nationals scored the go-ahead run in the seventh inning when Ryan Zimmerman singled to shallow right for the 6-5 advantage. They added an insurance run an inning later on Wil Nievas’ sacrifice fly that scored Josh Willingham.

That made a winner of reliever Drew Storen (2-0), who surrendered one hit in an inning of work. Matt Capps allowed the tying run to reach base in the ninth but recorded his 20th save.

Ian Desmond and starting pitcher John Lannan drove in runs in a three-run fourth that put Washington ahead by a run.

The Pirates took a 4-2 lead with three in the third and another on Neil Walker’s base hit in the fourth.

Pittsburgh reliever D.J. Carrasco (1-2) allowed a run on two hits to take the loss.