Having gone undefeated over their past four games in all competitions, Chelsea failed to make it five with a loss to Aston Villa.
The game was overshadowed by a touchline melee at the start of the second half.
The Seagulls had to come from behind three times to draw against Brentford.
Fiorentina maintained their fine run and push for European football by inflicting a third league defeat in a row on Inter.