Real Madrid’s Jacobo Ramon struck in the 95th minute to secure a 2-1 win over Mallorca, forcing Barcelona to wait for their La Liga title confirmation.
Mallorca’s Valjent opened the scoring, but Mbappé equalized for Real.
Despite the late drama, Barcelona need just a point against Espanyol on Thursday to clinch the title.
Real boss Carlo Ancelotti, departing for Brazil, praised his team’s fight.
Barcelona’s title charge was boosted by four El Clásico wins this season.