Sevilla striker Andre Silva matched a 25 year-old goalscoring record with his hat-trick on debut.
Andre Silva, on-loan from AC Milan, hit a treble in victory against Rayo Vallecano.
And it was the first time in 25 years such a feat has been achieved, with Romario the last to do similar.
Romario made his first appearance in Spanish football with the FC Barcelona shirt when scoring a hat-trick against Real Sociedad in the first day of the 1993/94 season.
Andre Silva managed just two goals for Milan last season.