Real Madrid was held to a 0-0 draw at Racing Santander on Wednesday, marking the first time the Spanish powerhouse has played consecutive league games without a win since the arrival of coach Jose Mourinho.
Madrid showed little improvement from its loss to Levante on Sunday despite a revamped lineup, and failed to create a single clear scoring chance before halftime.
Mourinho sent on Angel Di Maria, Kaka and Gonzalo Higuain in the second half, but Racing held on for the draw at El Sardinero stadium.
"The image we have shown in the last two games is not the right one," Madrid goalkeeper Iker Casillas said. "We have no other choice but to keep our chins up and look ahead to the games to come."
Also, Radamel Falcao scored a brace to lead Atletico Madrid to a 4-0 win over Sporting Gijon, while Malaga edged Athletic Bilbao 1-0.
Defending champion Barcelona visits Valencia later.
Mourinho made a number of changes from the starting 11 that lost at Levante.
With Pepe and Fabio Coentrao both injured and Sami Khedira suspended, Mourinho gave 18-year-old French defender Raphael Varane his first appearance of the season along with little used forward Jose Callejon and right back Alvaro Arbeloa. Regular starter Sergio Ramos was also left on the bench, while Lass Diarra got the rare nod in midfield.
However, the new-look team carried over Madrid's lackluster play from its loss over the weekend as Racing took the initiative through the fine performance of midfielder Papakouly Diop.
Racing pushed Madrid back into their area and Arbeloa had to scramble in the 17th to intercept forward Christian Stuani's backheeled pass intended for the unmarked Ariel Nahuelpan in the area.
Madrid finally had an effort on target just before halftime when Callejon tamely headed into the arms of Racing goalkeeper Antonio "Tono" Rodriguez.
Three minutes after the break, Racing midfielder Oscar Serrano forced a diving one-handed save from Casillas with a dipping blast in the best scoring chance for either side.
Mourinho sent on more attackers, but Racing held Madrid scoreless for the second straight game.
At Vicente Calderon stadium, Atletico completely outplayed last-place Sporting.
Atletico went ahead just before the half-hour mark when Falcao's strike took a deflection off defender Alberto Lora before landing in Sporting's net.
Defender Alvaro Dominguez headed home Atletico's second from a corner in the 68th, and four minutes later Falcao shook his marker and slotted into the corner to put the game beyond doubt.
The former Porto star then capped the win with a header in the 81st for his fifth goal in two games.
On the Costa del Sol, Malaga midfielder Santi Cazorla scored with an exquisite free kick to put his team ahead for good in the 62nd. It was the Spanish international's fourth goal of the season and third from a free kick.
Bilbao has now lost three straight under new coach Marcelo Bielsa.
Elsewhere, Levante got its second straight win by beating Rayo Vallecano 2-1 on goals by Valmiro "Valdo" Lopes and Sergio Ballesteros.
On Wednesday, Villarreal beat Mallorca 2-0 for its first win of the season. Sevilla drew 0-0 at Osasuna, and Real Sociedad edged Granada 1-0.
The newly promoted Betis tries to maintain its perfect record against Zaragoza on Thursday after Getafe hosts Espanyol.
