Lee went 3-for-4, including a solo home run, for the Cubs, who scored all their runs in the first four innings en route to their third consecutive victory.
Ramirez collected his two RBI on a single in the Cubs' three-run first inning.
Randy Wells (11-9) got the win. He gave up one run on seven hits and struck out five in six innings.
Dave Bush (5-8) took the loss after struggling through 1 1/3 innings. Bush surrendered six runs -- five earned -- on four hits and four walks.
Prince Fielder had a second-inning solo home run for Milwaukee. Ryan Braun brought the other Brewers run in with a sacrifice fly in the bottom of the ninth inning.