Artem Dovbyk struck a hat-trick inside seven minutes as minnows Girona powered back to the top of La Liga with a thumping 5-1 win over Sevilla on January 21.
After Real Madrid scraped a controversial 3-2 win over bottom side Almeria and Ferran Torres's own treble helped Barca win 4-2 at Real Betis, Girona demonstrated their title credentials.
The Catalan club, in the top flight for only the fourth season in their history, are shock challengers for the Spanish title and lead second place Madrid by a point, having played one extra game.
Struggling Sevilla, 17th, who in recent years have dreamed of a title tilt themselves, took the lead when Isaac Romero slotted home Adria Pedrosa's low cross to put the visitors ahead.
However Michel Sanchez's sparkling Girona responded forcefully with Dovbyk netting a quickfire treble.
The Ukrainian striker headed home at the far post to level the score in the 13th minute and then struck again two minutes later from Portu's cut-back.
The third was better still, a fine individual goal, with Dovbyk cutting in from the right and driving home from range.
Portu struck the crossbar as the hosts strutted their stuff at their Montilivi stadium.
Viktor Tsygankov slid home Girona's fourth early in the second half after good work by winger Savinho and substitute Cristhian Stuani rounded off the rout late on.