Real Madrid failed to take advantage of Barcelona suffering a shock defeat at Leganés as both clubs lost LaLiga matches on the same day for the first time since January 2015.
LaLiga champions and leaders Barca went down 2-1 at Butarque with Madrid loanee Óscar Rodríguez scoring the winner for Leganés, taking advantage of a Gerard Piqué error on Wednesday.
Madrid were therefore handed the chance to move top of the table but they instead suffered a first league loss under Julen Lopetegui in stunning style in Seville.
André Silva struck twice and Wissam Ben Yedder was also on target in the first half, with Pablo Machín's Sevilla in rampant form at the Ramon Sanchez Pizjuan midweek.
After six rounds of games, Barça and Madrid are level at the top of the league with Ernesto Valverde's men above their rivals on goal difference.
Defeats for Barca and Madrid was good news for Atlético Madrid, who sit two points behind in third having bounced back from their slow start to 2018-19.