Joey Harrington was 14-for-25 passing for 138 yards and an interception for Atlanta, which had two crucial interceptions in the final minutes of the game to hold on for the victory over the 49ers.
Warrick Dunn rushed 27 times for 100 yards and a touchdown for the Falcons.
Alex Smith was 17-for-38 passing for 149 yards and three interceptions for the 49ers, who have lost six games in a row.
Susan Sarandon: I was stoned at almost every awards show
Penelope Cruz named 2013's 'Best Body' by Fitness magazine