Barcelona earned head coach Ernesto Valverde a much-needed 2-1 LaLiga victory over Villarreal but Lionel Messi was substituted at half-time, cutting short his first start of the season.
After a modest start to the campaign Valverde's position had come under increasing scrutiny, yet goals from Antoine Griezmann and Arthur secured three welcome points on Tuesday.
Villarreal midfielder Santi Cazorla pulled a goal back before the break, but Barcelona's defence stood firm in the second half.
Finally able to make his 400th LaLiga start following a calf problem, Messi pulled up with a muscle injury just before the half-hour mark and despite returning to the field following treatment, he was replaced by Ousmane Dembele at the interval.
The Argentina forward, who picked up The Best FIFA Men's Player award in Milan on Monday, had been instrumental in his team's sixth-minute opener at Camp Nou.
Messi's cross following a corner picked out Griezmann and the France international headed in from a tight angle.
Barcelona added a second goal in the 15th minute with a thunderous strike from Arthur. Villarreal goalkeeper Sergio Asenjo could only stand and watch as the Brazil midfielder, afforded space and time, struck a powerful long-range shot into the top of the net.
The visitor pulled a goal back in equally spectacular fashion just before the break, though, when a slick passing move culminated with a fierce drive from Cazorla which flew beyond Marc-Andre ter Stegen.
Barcelona enjoyed the bulk of possession after the break and had a shout for a penalty when 16-year-old substitute Ansu Fati went to ground, though a VAR check backed up the referee's decision.
What does it mean? Win a welcome boost for Valverde
Barcelona was off the pace in LaLiga going into the game after two wins, two defeats and a draw from its opening five fixtures. The scrutiny on Valverde was beginning to intensify and this victory will have released the pressure valve to some extent.
It was far from its best but still managed to triumph, although Valverde will know it must improve amid renewed concerns over Messi's fitness.
Cazorla rolls back the years
Cazorla ran the game for Villarreal in midfield and capped his performance with a stunning goal. That the 34-year-old received a warm ovation from the home fans when substituted late in the game showed just how well he had played.
Ter Stegen looks suspect
While Cazorla's spectacular goal caught the eye, the position of Barcelona goalkeeper Ter Stegen must be questioned. The Germany international, used to periods of inactivity in home games, was caught out as he almost dived too far.
Villarreal is back in action on Friday when it hosts Real Betis while Barcelona heads to Getafe the following day.