Inter Milan laid down an early title marker on Saturday by handing out a 5-1 derby hammering to AC Milan and going it alone at the Serie A summit, while champions Napoli were held 2-2 at promoted Genoa.
Four wins from their opening four matches have Inter leading the pack with a perfect 12 points, two ahead of their other fierce rivals Juventus who beat Lazio 3-1 in the day's early match.
Milan sit a further point back in third after a humiliating first defeat of the season before they welcome Newcastle United in the Champions League on Tuesday.
Spurred on by the majority of a heaving and raucous San Siro crowd, Inter claimed their fifth straight derby win in all competitions thanks to a Henrikh Mkhitaryan brace, Marcus Thuram's rocket and two late strikes from Hakan Calhanoglu and Davide Frattesi.
Simone Inzaghi's side claimed the points with a display which showed why they got past Milan to reach last season's Champions League final and confirmed their status as early favourites to beat their local rivals to a 20th Scudetto.