Few believed Barcelona could achieve the impossible against Paris Saint-Germain, including former German international and ex-Barcelona star Bernd Schuster.

The former midfielder turned pundit said the team were a dying force after their first leg 0-4 rout in Paris and promised to appear at his regular Spanish radio show in a thong if they won the return leg.

Schuster, who appears as a pundit on "El Transistor" (The Radio) programme on the Onda Cero Spanish radio station was true to his word after the Spanish giants won the return leg 6-1 for an aggregate 6-5 triumph.

"Like a man you said you would come in (to the show) in a thong and you have come into the show in a thong," said the programme's presenter Jose Ramon de la Morena, who promised "don't worry, there will be no photos."

"It's a bit cold in here," replied Schuster on the show late Wednesday.

The former player and manager, aged 57, was not the only man who found himself out in the cold after Barcelona's miracle win.

Barcelona's former president Joan Gaspart, 72, went for a midnight dip off Barcelona's main beach after the game, fulfilling his promise to take an icy swim if his team did the impossible.

"Well done dad, you kept your word," said son Guillermo on Twitter with a photo of the event.

Others who had the temerity to bet against Barca were also left to pay the price.

Former Inter Milan and AS Roma midfielder Herbert Prohaska, a commentator on Austrian TV network ORF, dropped his trousers when Barcelona scored the winning goal and finished his live commentary in his underpants.