The Milwaukee Brewers launched the National League baseball playoffs with a 4-1 victory over the Arizona Diamondbacks in Saturday's opening game of their best-of-five division series.

Prince Fielder, the burly, bearded slugger who led Milwaukee with 38 home runs this season, belted a two-run shot in the seventh inning to increase the Brewers' lead to 4-0 on their way to victory.

The NL-best Philadelphia Phillies host the wild card St Louis Cardinals later Saturday in the opener of the league's other playoff series.

Zack Greinke (16-6) is scheduled to start for Milwaukee in Game Two of the series Sunday, while the visiting Diamondbacks counter with Daniel Hudson (16-12).