Barcelona collapsed to a 2-0 defeat on Saturday at Granada, with the minnows storming to the top of La Liga.
Atletico Madrid and Celta Vigo could not be separated in a goalless draw, and Diego Simeone's side dropped one place to third in the table.
Elsewhere, Villarreal defeated Real Valladolid 2-0, and Levante and Eibar shared a goalless draw.
Saturday's Results
Villarreal 2-0 Valladolid
Levante 0-0 Eibar
Atletico 0-0 Celta Vigo
Granada 2-0 Barca
La Liga Standings (Played, Won, Goal Difference and Points)
1. Granada: 5, 3, +5, 10
2.