Jason Bay homered and drove in four runs to lead Pittsburgh over the Chicago Cubs 6-2.
Bay, who's been slumping for more than a month, slugged a two-run homer off losing pitcher Carlos Zambrano.
Left-hander Shane Youman ran his record to 2-0 since being called up from Triple-A Indianapolis. He limited the Cubs to two runs over six innings.
Zambrano dropped to 10-7.