Jordi Alba and Neymar took advantage of two sensational passes from the No. 10 to settle an uncompromising showpiece, after both teams had been reduced to 10 men.
Lionel Messi proved Barcelona's hero in the Copa del Rey final, as the Argentine laid on both of his side's goals to seal a 2-0 victory over Sevilla at the Vicente Calderon.
Luis Enrique's side just managed to outlast Madrid pair Atletico and Real to defend their title in La Liga and it was another feat of endurance to see off Sevilla at the Vicente Calderon.
The Andalusian side could not replicate their second-half majesty of Wednesday's 3-1 Europa League final success against Liverpool, despite enjoying much of the play.
Javier Mascherano's first-half dismissal and Luis Suarez's withdrawal with a hamstring injury kept Barca pegged back throughout, but Ever Banega's dismissal in second-half stoppage time turned the tables.
Messi had been subdued throughout, but it was the Argentina star's inch-perfect pass that put Jordi Alba through to score in the 97th minute.
After Daniel Carrico saw red to add to the feisty atmosphere, Messi again hit top gear to set up Neymar's clincher, sealing a 28th Copa del Rey for Barca, whose Champions League quarter-final exit at the hands of Atletico stands as the only major blot on another stunning season.
Andres Iniesta turned in a true captain's performance of craft and guile throughout, and his superb scooped pass gave Suarez the first chance, but he smashed wide.
Sevilla's midweek hero Coke slashed wide after Vitolo presented him with a good chance, but the Andalusian fans were raucous after Mascherano received his marching orders after hauling down Kevin Gameiro on the edge of the box with the Frenchman clean through on goal.
Banega curled the subsequent free-kick over the wall and toward the top corner, but Marc-Andre ter Stegen showed his class with a superb save to tip the ball over the bar.
Gerard Pique nearly handed Barcelona the lead in the dying minutes of the first half, beating his marker to Ivan Rakitic's corner from the left, only to thump his header inches over.
The game was Sevilla's to lose following Mascherano's dismissal and Banega hit the post after a flowing move as they turned up the heat and Suarez's enforced substitution due to a hamstring injury appeared to leave Barca's chances crumbling.
Rafinha's introduction for the Uruguayan helped the Catalans control midfield better, but only a last-ditch block from Sergio Busquets prevented Grzegorz Krychowiak from opening the scoring from a corner.
Neither side could find the breakthrough, but momentum titled in Barcelona's favour in stoppage time as Sevilla were reduced to 10 men after Banega brought down Neymar just outside the area and Sergio Rico had to save from Messi and Jeremy Mathieu to force extra time.
However, Rico was left helpless as Alba raced onto Messi's pinpoint chipped pass over the defence and coolly slotted home.
Carrico was booked for a rough tackle on Messi, and his protestations earned another immediate yellow card, before Neymar sparked Barca's celebrations in earnest as he prodded home after more Messi magnificence.
