La Liga champions Barcelona have broken the 34-match unbeaten run in all competitions set by Real Madrid in 1989 after a 5-1 win against Rayo Vallecano on Thursday.
Luis Enrique's side matched the record when they came from behind to beat Sevilla on Sunday and hammered nine-man Rayo thanks to a Lionel Messi hat-trick to write themselves into Spanish football history.
Madrid set the previous record in the 1988-89 season under Leo Beenhakker when, having lost to Barca in the Supercopa de Espana second leg, they then avoided defeat until a trip to Celta Vigo in April.
Barca last tasted defeat against Sevilla at the Ramon Sanchez Pizjuan in October but, since then, have beaten the likes of La Liga title rivals Real Madrid and Atletico Madrid.
The European champions also saw off Arsenal to ensure a first-leg advantage in their Champions League last-16 tie while winning the FIFA Club World Cup and qualifying for the Copa del Rey final.
Barca boast an eight-point lead at the top of La Liga following their victory in Vallecas.