Goals from Cristhian Stuani and Portu in four second-half minutes cancelled out Isco’s opener for Madrid as Real fell eight points behind La Liga leaders Barcelona after just 10 games.
Madrid were making their first appearance in the deeply divided region since a violence marred October 1 referendum plunged Spain into political crisis.
As a reported one million people joined a rally in Barcelona in favour of Spanish unity on Sunday, just over 100 kilometres away in the pro-independence heartland of Girona, the visitors were expected to receive a hostile reception.
However, it was events on the field that proved far more troublesome for Zinedine Zidane’s men as they lost more ground on rivals Barcelona in the Liga title race.
Chants in favour of independence and “freedom” followed in the 17th minute as is common at Girona and Barcelona home matches to mark the fall of Catalonia in the Spanish War of Succession in 1714.
However, with plenty of Madrid fans present in the capacity 13,500 crowd, there were also plenty of Spanish flags on show.
In their first ever top flight match against the European champions, Girona looked keen to make a mark from the outset and were desperately unlucky not to go in front when Pablo Maffeo’s cross came back off the inside of the post 12 minutes in.
Seconds later, though, the ball was in the Girona net as Madrid broke immediately upfield and Isco tapped home the rebound after Bono parried Cristiano Ronaldo’s initial effort.
Girona continued to dominate the game and hit the woodwork again before half-time when Portu’s flicked header looped over Kiko Casilla and back off the inside of the post.
Real suffered an injury blow days before they travel to face Tottenham Hotspur in the Champions League on Wednesday as Raphael Varane was replaced by Nacho at half-time due to a muscular problem.
And the French international’s presence at the heart of the Madrid defence was badly missed as Stuani jinked past Nacho to fire Girona deservedly level nine minutes into the second-half.
Just four minutes later, Girona were in dreamland as Maffeo’s driven cross was flicked home by Portu and the goal was allowed to stand despite the striker appearing to be in an offside position.
Stuani had a huge chance to make the game safe when chipped the ball beyond Casilla and wide of the far post.
Yet, rather than mount a late comeback as they did so often on route to a first La Liga and Champions League double for 59 years last season, Madrid looked short of energy and ideas in the final half hour as Girona held out for a famous victory.