The Brewers survived a grand slam by pinch-hitter Craig Wilson.
Pittsburgh starter Kris Benson (5-9) got in immediate trouble, allowing a single to Eric Young, walking Scott Podsednik and hitting Geoff Jenkins with a pitch to start the game. Richie Sexson hit a grounder to third and Young scored on a wild throw by Aramis Ramirez.
A former Pirate, Vander Wal followed with his fifth career grand slam, blasting Benson's 0-1 pitch over the center field fence. Three of Vander Wal's grand slams have come this season.
Jenkins added a solo homer in the second off Benson and Brewers starter Wayne Franklin (6-6) helped himself in the third with an RBI single off reliever Salomon Torres that made it 7-0.