Barcelona hammered rivals Real Madrid 5-2 in a wild Spanish Super Cup Clasico final in Saudi Arabia on Sunday to win the first trophy of the Hansi Flick era.
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.
Madrid were hoping to avenge their 4-0 home defeat by Barcelona in October's LaLiga Clasico but instead were left battered and bruised by their arch-rivals in Jeddah.
After Mbappe's opener, Lamine Yamal levelled and Robert Lewandowski sent Barcelona ahead from the penalty spot, with Raphinha bagging a brace and Alejandro Balde also on target.
Rodrygo Goes pulled one back for Madrid with a free-kick but they could not capitalise further on their numerical advantage in a humiliating defeat for the European champions.
"I think today is a good day because we beat one of the best teams in the world, for the second time this season, Real Madrid, and this is unbelievable," Flick told reporters.
"We won a title here and we are really happy... today is a day to look positively at this team."
Real Madrid coach Carlo Ancelotti said his team's poor defending was the main reason for the heavy defeat.
"We defended badly and that cost us the game – they found their goals quite easily," Ancelotti told Movistar.
"We're sad, like all our fans, it's disappointing and we don't have to hide that... we have to look forwards, there's nothing else we can do."
Despite a strong Barcelona opening salvo it was Real Madrid who took the lead in the fifth minute with Mbappe's brilliant goal on the counter-attack.
The French forward, frustrated numerous times by the offside flag in the league defeat by the Catalans, broke loose on the halfway line after Vinicius won the ball back and, after bursting into the area, clipped past Szczesny.
It took a stunning individual goal from 17-year-old Yamal to level the scoreline, with the Spanish winger cutting in from the right before stroking home a low finish inside the near post in a similar style to former Barca great Lionel Messi, to whom he is often compared.
'ALWAYS SPECIAL'
Barcelona kept pushing and moved ahead through Lewandowski's penalty after Eduardo Camavinga arrived late and carelessly clattered Gavi.
Raphinha soon added Barcelona's third with a header from Kounde's cross from deep and they grabbed their fourth before halftime on the break.
Yamal and Raphinha combined and the latter slipped in Balde, who slotted past Courtois.
Barcelona continued in the same vein after the break and Raphinha netted the fifth with a neat dribble and finish after Marc Casado played him in.
The Catalans were reduced to 10 men when Mbappe sped in at the other end, rounding goalkeeper Szczesny, who brought him down outside the area and after a VAR review was dismissed.
Rodrygo, who earlier hit the post, rifled home the free-kick past Szczesny's replacement Inaki Pena.
Mbappe brilliantly teed up Jude Bellingham but the England international was denied by a superb Jules Kounde challenge in stoppage time.
The French forward also came close to scoring again himself on a fine individual display but Pena tipped away his effort.
"He was the best (Madrid player)," said Ancelotti, noting an improvement after Mbappe's hit-and-miss start to life at the club following his switch from Paris Saint-Germain.
"We can't always win, if we have to lose a cup, it's better that it's this one," said veteran Madrid midfielder Luka Modric.
Barcelona brought on playmaker Dani Olmo for his first appearance since he was registered to play for the club on a temporary basis, a controversial issue which overshadowed the semifinals earlier in the week.
However their five-star display offered a host of other talking points as Barca won a record-extending 15th Spanish Super Cup.
"It's really nice, it had been a season since we won a trophy, it's always special and on top of that in a Clasico against Real Madrid," Barcelona defender Kounde told Movistar.