LaLiga leaders Barcelona were held to a 1-1 draw away to Las Palmas on Thursday.
All seemed to be going to plan for Ernesto Valverde’s side in the first half, with Lionel Messi’s perfect 20-yard free-kick giving them the lead.
But just three minutes after the interval, Sergi Roberto tugged Matias Aguirregaray’s arm while defending a corner – the ball bounced off Barca’s Luis Suarez onto his own goalpost and grazed the arm of Lucas Digne.
It was unclear which possible offence had been punished but Jonathan Calleri did not worry, dispatching the resulting penalty emphatically into the top corner.
Barca dominated possession but could not find a winner and lead the standings by only five points from this Sunday’s opponents Atletico Madrid.
Deportivo Alaves pulled away from the relegation zone with a dramatic 1-0 win over Levante, who remain level on points with the drop zone.
Both teams were reduced to 10 men – Levante’s Chema receiving a straight red card in the first half, while Munir’s second booking levelled the sides 13 minutes from time – and Manu Garcia missed a penalty for Alaves before Victor Laguardia headed their winner from Ibai Gomez’s late free-kick.
Real Betis and Real Sociedad earlier drew 0-0, visiting keeper Miguel Angel Moya with excellent saves from Fabian Ruiz and Cristian Tello while Antonio Adan made a sharp save to deny Sociedad’s Alvaro Odriozola a winner.