Barcelona had led Real before the league took a three-month break in March due to the coronavirus pandemic, but Real rode an impressive string of 10 straight victories after the restart to overcome their bitter rivals.
Osasuna took the lead at Camp Nou in the 15th minute on Jose Arnaiz‘s right footed shot from the centre of the box to the bottom left corner. But Lionel Messi equalised it on a superb bend around the wall on a free kick in the 62nd, clipping the post past goalkeeper Sergio Herrera.
Luis Suarez, who came on as a second-half substitute, seemingly got the equaliser on a acrobatic volley in the 68th minute from Messi’s pass, but the goal was ruled offside.
Instead, Osasuna scored deep into stoppage on Roberto Torres’ goal to secure the win.
Barca, winners of the previous two La Liga crowns, will finish the season on Sunday against Alaves. They are back in action against Napoli on Aug. 8 in the second leg of their Champions League round of 16 clash.