Houston held a 4-2 lead before the Brewers scored three runs on right fielder Luke Scott's error. Tony Graffanino followed with his 5th home run in the month of June, a pinch-hit homer for the Brewers. That was eventually followed by Estrada's blast.
Matt Wise worked a scoreless sixth to get the win and improve to 2-1. Claudio Vargas got the start for the Brewers, who are now 12-2 in games he starts.
Ryan Braun had three hits, including a 2-run homer in the first. Carlos Lee went deep for the Astros.
A win today in the series finale would put the Brewers 14-games over .500, matching their season high. Jeff Suppan pitches the series finale for the Brewers.