Plying its trade in the Segunda Federacion, Cacereno more than held their own as the the European and LaLiga champion was unconvincing with Carlo Ancelotti having made nine alterations following the victory over Real Valladolid on Saturday.

But in the 69th minute, Rodrygo jinked onto his right foot before arrowing into the top-right corner and that proved be enough to see Madrid through.

Madrid's hopes of winning a 20th Copa del Rey, and their first since the 2013-14 campaign, remain alive but they made hard work of the victory.

It took until the 16th minute for the first shot on target of the contest, Dani Ceballos sending a tame long-range effort into the waiting hands of Ivan Moreno in the Cacereno goal.

The underdogs largely kept their opponents at bay during the first half and had a couple of attempts of their own, with David Grande testing Andriy Lunin before Carmelo Merenciano saw a shot deflected over the crossbar.

Ancelotti made a pair of changes at the break, but they had little impact as Cacereno continued to look the more threatening of the two teams, though Marco Asensio stung the palms of Moreno with a fierce drive.

Madrid was in need of a moment of quality, and Rodrygo provided one it in abundance when a mazy run into the box ended with the forward superbly curling home.

Ancelotti's men would not relinquish that lead, despite some late pressure, and they are in the hat for the next round.