Real Madrid conceded three-first half goals in a 3-0 loss at Sevilla on Wednesday, squandering a chance to go top of La Liga after Barcelona lost 2-1 at bottom side Leganes.
Portugal forward Andre Silva scored two in five minutes, and Wissam Ben Yedder added another in the 39th minute to seal Sevilla's convincing win at Ramon Sanchez-Pizjuan Stadium.
The result leaves Madrid and Barcelona level with 13 points after six matches. Madrid's only previous setback in the league had been a draw at Athletic Bilbao on matchday four.
Luka Modric scored for Madrid early in the second half but the goal was disallowed after VAR showed he was offside.
Marcelo appeared to injure a muscle midway through the second half but coach Julen Lopetegui couldn't replace him because he had already made all three substitutions.
Sevilla have won three in a row in all competitions, outscoring opponents 14-3. It moved three points behind Madrid and Barcelona in the league.
Silva, signed by Sevilla in the offseason, is La Liga's top scorer with six goals from as many matches.