Barcelona put in a clinical display to lift their first trophy in more than a year, having no silverware to show for last season.
Lamine Yamal, Robert Lewandowski, Raphinha and Alejandro Balde were all on target before halftime, after French forward Kylian Mbappe put Real in front in the fifth minute. Raphinha grabbed another in the second half while Rodrygo scored for Real.
Kylian Mbappe put Madrid ahead but a dominant Barcelona hit five in response before their goalkeeper Wojciech Szczesny was sent off in the second half.
"Our player Luka Modric is out of the game against Mallorca today because of a viral illness," said the Spanish champions in a statement.
Gavi put Barcelona ahead from close range after 17 minutes and teenage winger Yamal netted the second early after the break.
The Spanish champions were thrashed in Saudi Arabia by their bitter Clasico rivals and Xavi said his team gave a bad account of themselves.
The Brazilian winger, 23, is often criticised by opponents for going down easily, confronting officials and humiliating them with dribbles.
Vinicius Junior struck a first-half hat-trick to fire Real Madrid to Spanish Super Cup glory in a thumping 4-1 win over rivals Barcelona on Sunday in Saudi Arabia.
Real Madrid defeated Atletico Madrid 5-3 after extra-time in a pulsating battle in Saudi Arabia to reach the Spanish Super Cup final on Wednesday.
Marc-Andre ter Stegen saved twice from the spot to help Barcelona beat Real Betis 4-2 on penalties after a 2-2 draw on Thursday, setting up a Clasico Spanish Super Cup final.
Thibaut Courtois saved Jose Gaya's spot-kick to give Real Madrid a 4-3 penalty shootout win over Valencia after the teams had finished level at 1-1 after extra time in their Spanish Super Cup semi-final in Saudi Arabia on Wednesday.
Real Madrid shrug off the absence of the suspended Cristiano Ronaldo to cruise past rivals Barcelona 2-0 in the second leg of the Spanish Super Cup to cap a 5-1 aggregate win.
Barcelona’s midfield man Sergio Busquets says that the team are not giving up on the Spanish Super Cup even after the first leg 3-1 defeat to Real Madrid at the Camp Nou.
Three points from Barcelona's 3-0 win over Sevilla at the Camp Nou secures the Spanish Super Cup with a 5-0 aggregate victory.
Barcelona and star player Lionel Messi triumphed at the seventh edition of the Globe Soccer Awards in Dubai on Sunday, taking home the prizes for best team and best player.
Neymar believes Lionel Messi, Luis Suarez and himself were always going to be a success for Barcelona.
Barcelona boss Luis Enrique launched a staunch defence of his players after they came from behind without the injured Lionel Messi to beat Bayer Leverkusen 2-1 on Tuesday.
Cristiano Ronaldo can move ahead of Raul as Real Madrid's top goalscorer of all time as Los Blancos take on Athletic Bilbao.
