Xavi said Barcelona "deserved defeat" as the Spanish leaders suffered only a third loss in La Liga this season, going down 2-1 to Rayo Vallecano at a rowdy Vallecas.
Barca missed a golden chance to capitalise on Real Madrid's 4-2 loss to Girona 24 hours earlier, though Xavi's side remain 11 points clear with seven matches remaining.
In fact, it is Real who may be looking over their shoulders as Atletico Madrid cut the gap on their neighbours to two points with a 3-1 win over Real Mallorca, celebrating their 120th anniversary in style.
Xavi's side have won just one of their last four league matches – a narrow triumph over Atletico on Sunday – as they limp towards the finish line and a first title since 2019. "The league is not finished, this is the problem – we have to deserve La Liga, today we deserved defeat," Xavi told reporters. "What annoys me is that today we did not compete how the game required us to.