Dembélé saves the day with an absolute screamer to give Messi his 33rd trophy at the club.
The horror show concludes with a crushing defeat at the Bernabéu.
Embarrassment as Real Madrid crushes Barcelona at home with numerous poor individual performances.
Both players are set to be back after the international break.
A fine second half display combined with defensive compactness led to Barça's first win of the season.
Digne, Munir and Denis star as super subs as Barça gets closer to the trophy.
The German goalie hurts his left knee and will not be available against Sevilla on Sunday.