Barcelonas titles hopes were left hanging in the balance on Saturday as they crashed 3-2 away to Osasuna leaving Real Madrid the chance to open up a 10-point gap if they beat Levante on Sunday.
The reigning La Liga and Champions League winners have struggled on their travels this season with just four wins and succumbed to their third defeat in freezing conditions in Pamplona.
A double from Dejan Lekic put Osasuna in a commanding position before the break and while Alexis Sanchez reduced the arrears after 50 minutes, a clinical finish from Raul Garcia restored the two-goal cushion.
Substitute Cristian Tello hit Barcas second and there were chances at either end in the final stages but Osasuna held on.