Zidane responded by bringing on Eden Hazard, Toni Kroos and Marco Asensio but, after Ramon Lopez was dismissed for the hosts, Juanan claimed a historic winning goal with just five minutes remaining.

Real travelled to the Estadio El Collao without Sergio Ramos, Raphael Varane and Luka Modric in their squad, while Karim Benzema, Kroos and Hazard were named on the bench alongside first-choice goalkeeper Thibaut Courtois.

The 19-time cup winners failed to convince all evening but looked to have done enough to scrape into the last 16 courtesy of Brazilian defender Militao breaking the deadlock on the stroke of half-time.

However, with the clock ticking down, Solbes intervened in dramatic style by diverting the ball beyond Real's debutant keeper Andrey Lunin.

Zidane turned to his bench in order to avoid a headline-grabbing embarrassment but the changes failed to have the desired effect.

Alcoyano's hopes of claiming a second LaLiga scalp of the season after dumping out Huesca in the previous round were hit when forward Lopez was shown a second yellow card in the 110th minute.

Yet, they somehow managed to overcome that setback courtesy of midfielder Juanan's decisive finish to send their illustrious visitors back to the capital in shame and leave Zidane facing some awkward questions.