Real managed to win only 1-0 on the night at the Bernabeu and crashed out 4-1 over two legs to the tiny Segunda B club, who play in the same division as Real's youth team and have an annual budget more than four hundred times smaller than the La Liga giants.
Even the Madrid-based sports papers showed no mercy, as club and fans woke up to the fact that their expensively assembled squad can no longer match the title treble of Champions League, la Liga and Cup achieved last season by arch-rivals Barcelona.
"Complete disaster," screamed the headline in As. "Unprecedented farce," bellowed Marca above a picture of the celebrating Alcorcon players. The paper said it refused to put any photos of Real on the front page as they did not deserve it.
Fans chanted for Pellegrini to quit when he brought on defender Marcelo for midfielder Lassana Diarra with around 20 minutes left and the Madrid papers focused much of their ire on the Chilean.
Why were the uninspiring midfield pair of Mahamadou Diarra and Fernando Gago included in the starting lineup and striker Karim Benzema and creative midfielders Xabi Alonso and Guti left out of the squad altogether, asked Delfin Melero in Marca.
"The final whistle made possible an unprecedented situation," Melero wrote. "The Bernabeu booed its own team and coach and gave an ovation to Alcorcon, a team with spirit that demonstrated to Madrid that without pride and without a plan you're going nowhere."
FESTERING WOUNDS
Tomas Guasch, writing in As, said it was "completely unacceptable" that Pellegrini had changed the starting lineup he had used for the previous three matches and that was beginning to gel.
"And that there wasn't a single forward on the bench is absolutely unacceptable too," he added.
Club captain Raul said the squad needed time to adapt to the influx of new players, including record signing Cristiano Ronaldo, Kaka and Benzema.
"Sometimes it's difficult for a new project to go well right from the start," the striker told a news conference after training on Wednesday.
"Maybe it's taking too long but we have confidence in the coach and we cannot throw in the towel," he added. "We have to continue working as there is room for improvement."
El Mundo columnist Orfeo Suarez noted that Real president Florentino Perez was not known for his loyalty to coaches and said the spectacle of the fans calling for Pellegrini's head did not bode well for the Chilean.
"Madrid will make an effort to back the coach and quickly turn the page but wounds left behind can fester," he wrote.
Many papers did not miss the irony of an appearance by Perez on television earlier on Tuesday in which he played down the club's trophy expectations this season.
"We are at the start of a new project; we are giving it stability," the construction magnate, who spent around 250 million euros on players in the close season, told Cuatro.
"We aren't going to get nervous be
