Athletic Bilbao captain Carlos Gurpegui and goal-scorer Aritz Aduriz basked in the glory of their first trophy in 31 years.
Goalscorer Aritz Aduriz said Athletic Bilbao's Supercopa de Espana victory ranked right up there with the birth of his daughter.
Bilbao ended a 31-year wait for a trophy courtesy of their 5-1 aggregate victory over European and Spanish champions Barca, with Aduriz the difference with four goals.
A first-leg hat-trick at the San Mames was followed up by Aduriz's second-half goal at Camp Nou, when he followed up his initial shot - saved by Claudio Bravo - to tuck away into the unguarded net.
"It is impossible to write a script like that. Winning a title is the greatest thing that can happen to us and against Barcelona," Aduriz told Tele 5.
"It's incredibly satisfying to win a title with Athletic. For me it is the most we can hope for.
"We have something special that makes us strong. For us, this is amazing. The happiest day of my life was the birth of my daughter but apart from that [today is the happiest day].
"Many years we have not held anything in Bilbao and people of two or three generations ago deserve this."
Captain Carlos Gurpegui, a Bilbao youth product, said it was a long time coming for the Basque club.
"It's amazing. All my life I've dreamed to get a title. This is a dream come true. To win this title at Barcelona means a lot to us," Gurpegui added.