Life in La Liga without the injured Lionel Messi got off to a bad start for Barcelona on Saturday, as the reigning champions lost 2-1 away to Sevilla.
Goals from Michael Krohn-Dehli and Vicente Iborra in the space of six second-half minutes at the Ramon Sanchez Pizjuan gave the Andalusian hosts a lead they did not relinquish.
Barca pulled one back from the penalty spot through Neymar with 16 minutes to go.
But, despite laying siege to their opponents' goal in the closing stages of the contest, the Catalan giants proved unable to force an equaliser.
It leaves Luis Enrique with work to do in the weeks and months ahead as talisman Messi recovers from the knee injury he suffered early in Barca's 2-1 win at home to Las Palmas in their previous league game.
Such a significant victory against the title-holders will do much to ease the pressure on Sevilla's under-fire coach Unai Emery, following a poor start to the domestic season and their Champions League hammering at the hands of Juventus in midweek.
Barca came within inches of opening the scoring in the 24th minute, when a Neymar free-kick hit the post, ricocheted off goalkeeper Sergio Rico and rolled across the goal-line before Coke was able to clear.
They hit the woodwork again six minutes before half-time, Luis Suarez striking the top of the bar with a curling effort from outside the area.
The visitors had already gone close on two previous occasions through Neymar and Suarez, but Sevilla more than held their own.
Iborra, Kevin Gameiro and Marco Andreolli all missed presentable chances inside the opening 15 minutes, while a dangerous whipped cross from Benoit Tremoulinas required the intervention of Sergi Roberto to deny the hosts what would have been a golden opportunity to break the deadlock.
With a minute remaining in the first half, Ivan Rakitic's delicate flick released Suarez in on goal, but Tremoulinas was on hand to clear the danger as the Uruguayan hesitated.
Having weathered the storm, Sevilla took the lead seven minutes after the interval as Gameiro's dangerous ball across the face of goal was met at the back post by Krohn-Dehli, who smashed past Claudio Bravo.
The hosts doubled their advantage just six minutes later. Krohn-Dehli received the ball at his feet on the edge of the Barca area, cut inside and delivered a lofted diagonal pass toward the penalty spot, where Iborra, who had managed to stay just onside, rose to head the ball down, beyond Bravo and into the corner of the net.
Finally jolted back into life, Barca mounted a sustained assault on the Sevilla goal just after the hour mark.
Neymar was denied three times in as many minutes by Rico, but finally had his goal from 12 yards after Sandro Ramirez's shot hit the arm of Tremoulinas on the very edge of the area.
Sandro went agonisingly close to equalising for the visitors in the 78th minute, meeting a Luis Suarez cross to smash a shot against the crossbar, but consecutive defeats on the road leave Barca struggling to replicate their dominance of last season.
