The homer was Fielder's 30th this season. Casey McGehee had two hits including an RBI single and Ryan Braun had two hits for the Brewers, who averted a three-game sweep.
The winner was Mitch Stetter (4-1).
Starter Braden Looper surrendered a run and eight hits in seven innings.
San Francisco's run scored on Pablo Sandoval's two-out first-inning single.
Edgar Renteria and Randy Winn had two hits each for the Giants, who split a
six-game road trip.
The losing pitcher was Merkin Valdez (2-1).
Starter Jonathan Sanchez gave up a run and three hits in six innings with three walks and nine strikeouts.
Copyright 2009 by United Press International.