The Reds took a 6-1 lead into the ninth inning, but a fielding error by pitcher Jared Burton opened the door to a huge Milwaukee comeback.
Milwaukee scored the tying run in the ninth on a base hit by Casey McGehee and the Brewers still had the bases loaded with only one away.
Mike Cameron then lifted a fly ball to left field and Ryan Braun tried to tag up and score the winning run after the catch but left fielder Darnell McDonald threw Braun out at home to send the game into extra innings.
Cameron was also stranded at third in the 12th inning after a two-out triple and Cincinnati gave the Brewers no more chances. Votto homered to lead off the 13th against Todd Coffey (4-3) and Nix hit his shot with two away.
Danny Herrera (2-4) worked the final two innings to get the win.
Copyright 2009 by United Press International.