Spanish giants Barcelona and Real Madrid grabbed last-gasp 2-1 victories after a rash of red cards and crowd trouble in the Primera Liga on Saturday.
Barcelona came from behind to beat Espanyol with a Lionel Messi penalty in the last derby at the Montjuic stadium. The game turned around after crowd disturbances forced the referee to take the players off the pitch for almost 10 minutes.
Ruud van Nistelrooy gave Real Madrid the points at Real Betis, where each team had a player sent off, to keep the champions a point behind leaders Villarreal who won 1-0 at promoted Sporting Gijon thanks to striker Giuseppe Rossi.
Villarreal have 13 points from five games but, with the bulk of the weekend matches being played on Sunday, Valencia could regain top spot if they win at home to Deportivo Coruna.
Barcelona, who face Shakhtar Donetsk in the Champions league on Wednesday, are in third place two points behind Real Madrid.
They were losing 1-0 at Espanyol when television pictures showed a flare being lobbed from the upper stand towards the fans below, leading referee Medina Cantalejo to stop the match.
Thierry Henry equalised after the game restarted when he picked up a long Xavi pass. Espanyol's Cameroon goalkeeper Carlos Kameni denied the France striker from close range but the ball rebounded off Daniel Jarque to land at Henry's feet.
Messi scored from the spot in the fifth minute of stoppage time after striker Samuel Eto'o was brought down. Barca keeper Victor Valdes had gifted Espanyol the lead in the 20th minute when he palmed the ball to Ferran Corominas from under the bar.
Real, who visit UEFA Cup holders Zenit St Petersburg in the Champions League on Tuesday, had a hard time collecting the points in Seville after a convincing first half performance.
Their Argentina defender Gabriel Heinze opened the scoring in the 19th minute with a close-range header that flew inside the far post after a free kick from the left by Ruben de la Red.
Betis equalised early in the second period when Madrid's Brazilian defender Marcelo conceded a penalty and was sent off after a reckless challenge from behind on Damia Abella.
Casillas got a hand to Sergio Garcia's spot kick but the Betis striker slammed the rebound into the net. Garcia was then sent off after being shown a second yellow card in the 82nd minute for a tackle on substitute midfielder Royston Drenthe.
In stoppage time, Van Nistelrooy beat his marker Juanito with a powerful run down the right and fired a low cross shot past Castro Espinosa to secure the points for the visitors.
Villarreal, who host Celtic in the Champions League on Tuesday, had to wait until the second half before opening the score at Gijon when Italian Rossi picked up a loose ball in the area and gave Sporting goalkeeper Ivan Cuellar no chance.
It was a frustrating night for Sporting whose Croatian striker Mate Bilic spurned several chances. They are rooted to the bottom without a point, having already conceded 20 goals.