Real Madrid suffered a shock defeat away to Levante as city rivals Atletico Madrid enjoyed a first victory of the new Primera Liga season.
Arouna Kone scored the only goal of the game midway through the half as Levante's unbeaten start to the campaign continued with a surprise 1-0 home success over Real.
Jose Mourinho's side had scored 10 goals in their opening two matches, but could not find a way past Levante after also being reduced to 10 men in the first half.
Sami Khedira was sent off for a second bookable offence four minutes before the interval and Levante took advantage to grab the winner through Kone.
Summer signing Radamel Falcao grabbed his first league goals for Atletico as his new club thrashed Racing Santander 4-0 at Vicente Calderon.
Falcao was brought in from Porto to help fill the void created by the departures of Sergio Aguero and Diego Forlan, and he scored Atletico's first Primera Liga goal of the season on 23 minutes.
He added another from the penalty spot before half-time and completed his hat-trick on 55 minutes before substitute Adrian wrapped up the scoring on 78 minutes.
Real Zaragoza were another team to score for the first time this season on Sunday as Luis Garcia's brace snatched a 2-1 home win over Espanyol.
Garcia opened the scoring for Zaragoza just before the half-hour mark, but Espanyol levelled on 71 minutes through Javi Lopez.
However, Lopez was sent off for a second bookable offence four minutes from time and Garcia then pounced for Zaragoza's winner two minutes into stoppage-time, having earlier missed a penalty.
Real Betis maintained their 100 per cent start to the season by hanging on for an impressive 3-2 success away to Athletic Bilbao.
The visitors were quickly in command at San Mames as Benat and Nacho scored inside the opening 13 minutes before Bilbao reduced the arrears through Oscar de Marcos on 38 minutes.
However, Salva Sevilla's penalty restored Betis' two-goal cushion on the stroke of half-time and Mario was then sent off for the away side with 15 minutes to go.
Bilbao set up a tense finale when David Lopez converted from the penalty spot on 87 minutes, but home defender Fernando Amorebieta was dismissed for the ninth time in his career in stoppage-time.
Rayo Vallecano maintained their unbeaten start to the season as Michu's fourth minute goal was enough to claim a 1-0 win away to Getafe.