Wildcard Ferrero, winner in 2002 and 2003, followed up his impressive victory over second seed Marat Safin on Thursday with more textbook claycourt tennis to win in one hour, 13 minutes.
It was Ferrero's first quarter-final since Valencia this time last year, after which his ranking went in to freefall following a bout of chicken pox and various nagging injuries.
The former French Open winner, bidding to equal Austrian Thomas Muster's three titles here, will play defending champion Guillermo Coria or Spain's David Ferrer in Saturday's semi-final.
In the other half of the draw, top seed Roger Federer takes on French teenager Richard Gasquet while Spain's in-form Rafael Nadal plays French Open champion Gaston Gaudio.
Friday's play was delayed as a mark of respect for the late Prince Rainier III of Monaco, whose funeral earlier in the day brought the principality to a standstill.
