Michael Wacha (2-5) gave up a career-worst eight runs in four innings and has lost five consecutive decisions for the first time. The 24-year-old right-hander was a 17-game winner last season and the NL championship series MVP as a rookie in 2013, but this season has a 5.04 ERA.
Jorge Soler drew a bases-loaded walk in the first and hit a two-run home run in the fifth.
The six-run inning was a season-best for the NL Central leaders, who snapped their first three-game losing streak of the season. David Ross had an RBI double for his 500th career hit and Kris Bryant had an RBI single in the outburst.
Hammel (6-1) bounced back from his first loss in his previous start.
