"This is not good enough," Mazzarri told reporters.
"If we want to be up there challenging we need more. We need consistency, it makes me angry when he show up and have these unexplainable performances."
Elsewhere, Catania moved up to seventh and within sight of a Europa League place with a 1-0 home over Bologna.
Valter Birsa's 87th-minute winner handed Torino a 2-1 victory over Atalanta, while Juraj Kucka's 33rd-minute goal was enough to see Genoa creep further away from the drop zone with a 1-0 win over Udinese.
A Marco Sau double for Cagliari assured a 2-0 win away to new boys Pescara and moved the Sardinians up to 14th.
In France, Paris Saint-Germain saw its lead at the top trimmed to just three points after it suffered a shock 3-2 defeat at Sochaux.
Without David Beckham, who is expected to make his debut in next weekend's clash with Marseille, PSG took a 29th minute lead through Alex.
Sochaux hit back to lead 2-1 with 54 minutes on the clock before an own-goal brought PSG level with 14 minutes remaining.
But with the game seemingly heading for a draw, Cedric Bakambu popped up to lash home a shock winner and leave PSG shattered.
Lyon remains in second place following a crushing 4-0 win at Bordeaux, while Reims and Saint-Etienne shared a 1-1 draw.