The Reds reached the halfway point of their season at 31-50, the worst record in the majors. It's their worst midpoint mark since they also were 31-50 in 2005.
This one meant a lot to Lohse (4-10), who had already reached double digits in losses and wanted to set things right after a rough time last Saturday in Seattle, where he gave up a career-high eight runs in a 9-1 loss.
His sacrifice fly completed a no-frills rally in the sixth off Adam Wainwright (6-7), who let the game get away because he couldn't find the strike zone. The Reds scored three runs on a single, three walks, a hit batter and the sacrifice fly.
David Ross also had a two-run homer off Wainwright, who failed to retire a batter in the sixth for his shortest start since May 15.
The NL's worst bullpen - Reds relievers have a league-leading 18 losses - preserved the win for Lohse, who gave up five hits and one run in seven-plus innings while striking out eight.
In another demonstration of manager Jerry Narron's lack of faith in his setup relievers, closer David Weathers got the final five outs in a non-save situation.