Barcelona's quest for an unbeaten La Liga season came to a shocking end with a 5-4 defeat away to Levante on Sunday.
Barca wrapped up the league title two weeks ago, but coach Ernesto Valverde said his team were focused on becoming the first Spanish side to go unbeaten through an entire league campaign since Real Madrid did it in 1931-32, when the season lasted only 18 games.
But Levante, who had not beaten Barcelona in the league since 1964, ended the champions' dream in the second-to-last game of the season as Emmanuel Boateng recorded a hat trick.
Philippe Coutinho scored three goals in an attempt to rally his side, which had left Lionel Messi out of the squad, and Luis Suarez added a 71st-minute penalty, but the comeback came up short, ending Barcelona's run of 43 games unbeaten dating to last season.
Levante took the lead in the ninth minute when Jose Luis Morales cut the ball back from the endline for Boateng to tap in off the underside of the bar.
On the half-hour mark, Sasa Lukic played Boateng into the box, and the Ghanaian rounded Marc-Andre ter Stegen to become the first player this season to score twice in a game against Barcelona in any competition.
Coutinho got a goal back eight minutes later with a blast from the top of the box to bring Barcelona into the dressing room down 3-1.
But the hosts came out for the second half on fire and made it 5-1 within four minutes, with Enis Bardhi scoring from distance before Boateng completed his hat trick on the counterattack.
Boateng became the first player to score a hat trick against Barcelona since Diego Forlan did it for Villarreal in 2005.
But Coutinho sparked Barcelona into life before the hour mark by firing home from 9 yards after Levante failed to clear their lines, then made it 5-3 four minutes later with a deflected shot on the half-volley from 20 yards for his first hat trick since his transfer from Liverpool.
Suarez cut the deficit to one from the penalty spot in the 71st minute after Boateng tripped up Sergio Busquets, but the Uruguayan striker then missed a chance to equalise with a header.