Nate McLouth and Rick Ankiel both reached on walks and advanced to second and third on a wild pitch by Jose Veras (3-3). Infante then delivered a two-out hit to give the Braves a win in the first of three games against the Marlins at Turner Field.
Mike Dunn (2-0) was credited with the win after getting the final out in the top of the 11th. Starter Tommy Hanson yielded only one run over 7 2/3 innings for the Braves, who entered the contest one-half game behind San Diego in the National League wild-card race.
Atlanta's post-season chances took a possible hit, however, when slugging third baseman Prado left the game after injuring his hip. He limped off the field after making a leaping catch in the fourth inning to rob Dan Uggla of an extra-base hit.
Prado's status was listed as day-to-day with a left hip pointer.
Marlins starter Anibal Sanchez held the Braves to one run on five hits over seven innings.