LaLiga leaders Barcelona saw a six-match winning streak halted after a 2-2 draw at Real Sociedad - which could see them knocked off the top of the table ahead of El Clasico.
Barcelona boss Ernesto Valverde had warned Saturday's trip to San Sebastian would be a stern test, and so it proved.
Mikel Oyarzabal had given the hosts the lead through a 12th-minute penalty, but Antoine Griezmann equalised ahead of half-time, scoring against the club where he began his career.
Luis Suarez put Barcelona ahead shortly after the restart, knocking in a square pass from Lionel Messi, but Alexander Isak levelled things up at 2-2 after Marc-Andre Ter Stegen had failed to deal with a cross.
Barcelona will be replaced at the top of the table by Real Madrid if their rivals win at Valencia on Sunday, with Los Blancos set to come to the Nou Camp on Wednesday
In the evening kick-off, Atletico Madrid beat Osasuna with second-half goals from Alvaro Morata and Saul Niguez.
Elsewhere, Athletic Bilbao played out a goalless draw against Eibar, while in Saturday's lunchtime fixture, a late goal from Enis Bardhi gave Levante a 2-1 win at Granada.
In the Bundesliga, Philippe Coutinho scored a hat-trick as Bayern Munich came from behind to thrash Werder B