Barcelona broke a 27-year old Spanish record by going 35 games unbeaten in all competitions with a 5-1 thrashing of nine-man Rayo Vallecano.
Lionel Messi scored a hat-trick – his 35th – as the hosts fell apart after Ivan Rakitic’s opener.
Diego Llorente and Manuel Iturra were both dismissed for Rayo, whose only goal was scored by Manucho.
Luis Suarez also had a penalty saved before Arda Turan completed the rout to move Barcelona eight points clear.
