Brewers starter Jeff Suppan gave up five runs -- all with two outs -- and ten hits in only five innings of work. Keppinger's three-run double in the third set the tone.
The first-place Brewers saw their division lead over the Chicago Cubs slip to two games because the Cubs beat St. Louis 7-to-1.
Earlier today, Milwaukee traded three pitching prospects to San Diego for reliever Scott Linebrink, providing another setup man for closer Francisco Cordero.
Also, the game marked the return of center fielder Bill Hall who came off the disabled list, completing his fast recovery from a severe ankle sprain three weeks ago.
He had one hit in three at bats.