On October 3, 2007, when Arizona faced the Chicago Cubs in the first game of the 2007 National League Division Series, Reynolds' seventh-inning home run off of Cubs reliever Carlos Mármol led the Diamondbacks to a 3–1 victory and a three-game sweep of the division series. Reynolds also hit a home run in Game 3 of the 2007 National League Championship Series against the Colorado Rockies. The Diamondbacks eventually lost the league championship series to the Rockies in just four games.