Real Sociedad stumbled to a 1-1 draw at Real Mallorca on Sunday in La Liga, with their bid to finish in the top four losing steam at an alarming rate.
The Basque side have just one win in their last nine matches across all competitions and were frustrated by hosts Mallorca, 10th.
Real Sociedad remain fourth, level on 45 points with third-place Atletico Madrid, who visit Girona on Monday.
Real Sociedad captain Mikel Merino was dismissed late on for a late lunge on Abdon Prats to make a disappointing afternoon worse still.
Beaten in the Europa League last 16 first leg by Jose Mourinho's Roma, Real Sociedad were trying to bounce back with their first league win in four games.
Carlos Fernandez fired the Basque side ahead after just three minutes with a well-taken strike.
Veteran playmaker David Silva fed the forward, who drilled into the bottom corner.
Real Sociedad dominated the first half but could not extend their lead, and soon paid the price.
Lee Kang-In levelled for Mallorca after defender Jon Pacheco stumbled, with the South Korean forward slipping in behind and finishing well.
Merino was sent off for a dangerous lunge on Prats after losing the ball with a poor touch, in the final stages.
Real Betis, fifth, are four points behind La Real and face sixth-place Villarreal later Sunday, before leaders Barcelona visit Athletic Bilbao.
