Barcelona moved 11 points clear at the top of La Liga standings after a 0-1 win over Villarreal in a scrappy encounter.
Pedri’s goal after 18 minutes was enough to give the 26-time champions their sixth consecutive league win.
Xavi’s side have conceded just seven goals in the league and their only defeat came to Real Madrid in December.
They took advantage of Real’s absence from the weekend’s fixtures because of their participation in the FIFA World Club Cup to extend their lead.
Ancelotti’s side will return to league action against Elche on 15 February after beating Al-Hilal 5-3 in the Club World Cup final, but face a huge task to overhaul their historic rivals.
READ MORE: La Liga: Barcelona Go Eight Points Clear After Defeating Sevilla
Eight bookings and a serious-looking leg injury to Villarreal’s Francis Coquelin, who was carried off on a stretcher in distress, disrupted the flow of the match.
A deft touch from striker Robert Lewandowski allowed Pedri to slip in between two defenders to roll the ball past Pepe Reina for the only goal with one of the moments of great quality of the night.
Alex Morales had Villarreal’s best chances of the night as the side coached by former Barcelona manager Quique Setien missed out on a chance to go into fifth place.
