Gerard Lopez’s side did most of the hard work last weekend, winning 4-1 away from home, and finished the job off with a goalless draw on Sunday evening.
The win means Barca return to the Segunda Division after a two-year absence and the result will be a huge boost to the whole club.
Sergi Palencia captained the side to victory with Lopez's team featuring a host of players who have been tipped to make the breakthrough into the senior set-up.
Marlon Santos, who made the step up at the end of last season, featured at centre-back with Marc Cucurella, who has been linked with a host of clubs recently, at left-back.
Meanwhile, in midfield Carles Alena impressed again, and amid all the talk of midfielders at the moment, might he be handed a chance to impress next season?
Barcelona B line-up: Suárez: Palencia, Marlon, Martínez (Ruiz), Cucurella: Aleñá, Ferran, Gumbau: Alfaro, Romera (Xemi), Cardona (Borja).