Two of the prime candidates to gatecrash the top four this season go head-to-head at Estadio Benito Villamarín.
The same clubs, Real, Barça, Atleti and Sevilla, have occupied the top four spot in each of the last three seasons but, with Sevilla a shambles, a vacancy could be opening up.
Both of these two sides have made excellent starts to the season, meaning both begin the weekend in the Champions League places.
Villarreal are one point better off after they hammered Elche 4-0 at Estadi Ciutat de València last weekend.
Gerard Moreno, Giovanni Lo Celso, Francis Coquelin and José Luis Morales the scorers.
Before this, Unai Emery’s team had defeated both Real Valladolid and Atlético Madrid on the road, before being held to a goalless draw by Getafe.
Real Betis meantime began the season with three successive victories, but then took on Real Madrid in last weekend’s top of the table clash.
Sergio Canales’ first half equalised proved to be in vain at Estadio Santiago Bernabéu as the reigning champions ran out 2-1 winners.
Both clubs were then involved in European action on Thursday night, with both picking up maximum points.
Los Verdiblancos began their European campaign by beating HJK 2-0 in Helsinki; Willian José with both goals.
Over in the Europa Conference League, Villarreal ousted Polish champions Lech Poznań in a seven-goal thriller.
Álex Baena bagged a brace, Samuel Chukwueze and Coquelin were also on target, as el Submarino Amarillo prevailed 4-3 in Valencia.
Will there be a winner in this showcase Sunday night clash?