A Philippe Coutinho opener sent Barcelona on their way, while a Luis Suarez hat-trick and a late Arturo Vidal goal proved far too much for Madrid, who could only muster a single goal from Marcelo.
The defeat continues a run of terrible form for Julen Lopetegui’s side, as the coach's seat grows increasingly hot with Madrid dropping further down the La Liga table.
While a victory over Vikoria Plzen in the Champions League provided a temporary reprieve for Lopetegui, Barcelona returned his side to their now-familiar struggles in the league, where they have not won in five contests.
That stretch saw Madrid set their longest goalless period since 1985, and very nearly surpass their longest streak of all time.
A draw against rivals Atletico is the only point Real have managed in the league since a victory over Espanyol on September 22, and Madrid are now on a three-game Liga losing streak.
While that type of streak may not be alien to most clubs, it is at Madrid, who have not endured a such a poor run of form in almost a decade.
The last time Madrid suffered three straight losses came back at the end of the 2008-09 season, when the club dropped five straight Liga contests to close out a difficult campaign.
Ramos himself had been a midseason replacement for Bernd Schuster, who departed the club in December of 2008.
The end of Schuster’s reign had seen two straight defeats in the league that season, with Ramos’ debut coming in the first Clasico of that Liga campaign - also a defeat for Madrid.
However, since suffering those two three-match losing streaks in La Liga that season, Madrid had managed to avoid such runs in the decade since until this current sequence of Lopetegui’s side.