One of Bell's hits was a two-run homer in the bottom of the second inning.
Starter and winner Dave Bush had one run, two hits, and two RBI; Tony Graffanino hit an RBI single and drove in a run with a bases-loaded walk; Prince Fielder also drew a bases loaded walk; and a run scored on an error by center-fielder Steve Finley for the Brewers (70-83), who have won three of their last four games.
In 7 1/3 innings, Bush (12-11) gave up four runs and five hits.
Moises Alou hit two homers and knocked in three runs; Shea Hillenbrand hit a solo homer; and Alou had two of the five hits for the Giants (75-77), who have lost three of their last four games.
The losing pitcher was Matt Morris (10-15).