Champion Juventus underlined its Serie A title credentials by going top as Inter Milan was humbled 3-1 by a Francesco Totti-inspired Roma at the San Siro.
AC Milan, which finished runner-up to Juventus last season but stuttered against Sampdoria last week, got its scudetto campaign back on track Saturday when Giampaolo Pazzini struck a hat-trick in a 3-1 win away at Bologna.
In Sunday's earlier match Juventus produced a similarly commanding performance in a 4-1 win away to 10-man Udinese which included a brace from Sebastien Giovinco and gave it two wins from two.
While Udinese chief Giampaolo Pozzo was furious at the referee's decision to send off his goalkeeper Zelijko Brkic for a foul on Giovinco, the little striker known as the "Atomic Ant" was unforgiving.
"Today it was important to win and give a signal and we did that," said Giovcinco, who produced a second half brace to add to Arturo Vidal's first half penalty and a goal from Montenegrin Marko Vucinic.
While there were deserved wins for Napoli and Lazio, Roma's humbling of Inter Milan was the talk of the night.
After 15 minutes former Italy marksman Totti was given space on the left and delivered a perfectly-weighted cross for Alessandro Florenzi to head superbly past the outstretched Luca Castellazzi and into the bottom corner.
Inter striker Diego Milito twice came close with a header on the half hour and an angled shot five minutes before the interval that was blocked by a defender.
And after the restart Inter, which hammered promoted Pescara 3-0 away last week, got back on level terms albeit in somewhat fortuitous fashion.
Antonio Cassano, who until last week had been AC Milan's main striker, latched onto a long ball from Wesley Sneijder, turned while holding off two defenders and saw his deflected shot rise high and drop into the goal.
His celebrations, less than an hour after being left out of Casare Prandelli's most recent Italy squad, were exuberant but soon overshadowed.
Roma striker Daniel Osvaldo, who was red-carded for a second bookable offence late in the match, missed two great chances to put Roma ahead while in prime position to score.
But his vision and sense of good timing finally paid off when he beat Inter's failed attempt to spring the offside trap and ran onto a Totti long ball to chip the onrushing Castellazzi.
Inter's hopes of launching any kind of fightback were extinguished nine minutes from time when Osvaldo's chip with the outside of his right boot from the left flank allowed second-half substitute Marquinho to somehow beat the diving Castellazzi from the tightest of angles.
Totti, whose Roma side could only eke out a late draw at home to Catania last week, said: "We put in a great performance, because it's not easy to come to (Inter) Milan and win in front of a crowd like this.
"These three points will give us confidence because we came in for some criticism after our result last week. This is the best kind of answer we can give."
Sampdoria completed a double over Serie A champion Juventus with a 3-2 win at a rainswept Stadio Luigi Ferraris - to end the season in 14th place.