Darren Bent’s strike on five minutes looked to be going comfortably through to Pepe Reina until it hit a big red balloon, changed direction and ended up in the back of the net.
Television cameras later showed that the balloon was punched onto the pitch by a young Liverpool fan just moments before the goal.
Without Steven Gerrard and Fernando Torres, Liverpool looked lacking and struggled to break past a stubborn Sunderland defence.
The result means Liverpool have lost four of their opening nine Premier League games this season with Manchester United to come at Anfield next weekend after the midweek Champions League clash with Lyon.
Team Line-ups and Substitutions
Sunderland: Gordon, Bardsley, McCartney (Henderson 46), Turner, Ferdinand, Reid, Malbranque, Cana (C), Cattermole (Zenden 58), Bent, Jones (Campbell 66). Subs: Fulop, Nosworthy, Da Silva, Healy.
Liverpool: Reina, Johnson, Agger, Aurelio, Benayoun, Kuyt, Babel (N’gog 81) , Lucas, Carragher (C), Spearing (Mascherano 72), Skrtel (Voronin 72). Subs: Cavalieri, Riera, Insua, Kelly.