MADRID, Sept 27 (Reuters) - Villarreal are challenging Spain's established order after Manuel Pellegrini's new-look side made it four wins from five to top the Primera Liga for the first time in their history in midweek. This after some bad omens at the start of the season, with top scorer Diego Forlan sold to Atletico Madrid and centre-back Roberto Ayala walking out on them without playing a game. The decision to leave Argentina playmaker Juan Roman Riquelme in the stands looked reckless, and a 5-0 drubbing from Real Madrid early on did not auger well for modest Villarreal. But that has quickly been forgotten. On Wednesday, they won 2-0 at Racing Santander with goals from Nihat Kahveci and young Italian striker Giuseppe Rossi, taking his overall tally to four. Champions Real Madrid were not playing Real Betis until Thursday evening when they could reclaim the top spot, but still Pellegrini could not hide his satisfaction. 'The team are in good shape in every sense. Their morale is high and everyone feels important. This has helped us overcome the setbacks we have had,' Pellegrini said. 'I hope this strong start will help us to have a good campaign.' They host Athletic Bilbao on Sunday when Valencia, who are level on 12 points, visit Recreativo Huelva. On Saturday, the mismatch of the weekend sees Barcelona visit bottom club Levante, who have one point from five games and the worst defensive record in the league. Barca have won three games in a row, scoring nine times and in a whirlwind first half against Real Zaragoza in midweek looked back to their very best. 'In the last two games we have shown that we haven't forgotten how to play,' said Argentina forward Lionel Messi, who scored two in the 4-1 win. Ronaldinho is still recovering from a calf strain and Italy defender Gianluca Zambrotta will be out after tearing a thigh muscle in the Zaragoza match. In-form Atletico Madrid are at home to Osasuna on Sunday having scored 10 goals without conceding in their last three matches in all competitions, while two teams in need of a lift, Sevilla and Zaragoza, meet on Saturday. Sevilla have lost three on the trot for the first time under coach Juande Ramos and Zaragoza have just one win under their belts. Getafe, still searching for their first win, host near neighbours Real Madrid on Sunday.