AC Milan clung on to beat Parma 5-4 away in Serie A on Sunday despite an dreadful defensive display which included Mattia De Sciglio scoring an extraordinary own goal from near the halfway line late in the match.
Goalkeeper Diego Lopez injured himself in a vain attempt to stop the ball and had to hobble through injury time with Milan having already made three substitutions.
Inter Milan had a much more straightforward time as they routed hapless Sassuolo 7-0 for the second season in a row with Argentine striker Mauro Icardi grabbing a hat-trick and Pablo Daniel Osvaldo scoring twice. Mateo Kovacic and Fredy Guarin were also on target.
Rafael Benitez's problems at Napoli mounted as they lost 1-0 at home to modest Chievo after Gonzalo Higuain missed a first-half penalty and Maxi Lopez struck early in the second half for the visitors.
Benitez, who took a week off before the match, was already under pressure after Napoli lost their Champions League playoff to Athletic Bilbao.
Stefano Okaka scored a brilliant individual goal to help Sampdoria beat Torino 2-0 and was then told by coach Sinisa Mihajlovic that it was time to make up for wasting "six or seven years" of his career.
Juventus, AS Roma and Milan are the only teams with six points from the opening two games.
Fernando Torres missed his Milan debut with an ankle sprain but that barely seemed to matter as Giacomo Bonaventura put them ahead in the 25th minute.
Antonio Cassano scored against his old club to level two minutes later but a Keisuke Honda header and Jeremy Menez penalty put Milan 3-1 ahead at halftime.
Felipe pulled one back early in the second half and Milan had defender Daniele Bonera dismissed for a second bookable offence but, as Parma pressed for an equaliser, midfielder Nigel de Jong scored a fourth for Milan on the break.
Alessandro Lucarelli headed one back for Parma five minutes later but the hosts lost their one-man advantage when Felipe was sent off for a second yellow.
Menez seemed to have made the game safe with a clever back-heeled goal for Milan's fifth but the drama was not over.
De Sciglio played the ball back to Lopez from near the halfway line but the ball caught the goalkeeper off guard and he appeared to sprain his thigh as he twisted to try to stop it.
Parma though failed to test him and Milan held on for the win.
Napoli missed a host of chances against Chievo, including a Higuain penalty which was brilliantly saved by Francesco Bardi midway through the first half.
Lopez scored Chievo's winner with an angled drive seconds after Bardi made another good save to deny Juan Camilo Zuniga.
"The fact that we had so many shots on goal shows that we did something right," said Benitez.
Okaka scored the best goal of the day when he ran from the halfway line, held off a challenge from Emiliano Moretti and flew past Kamil Glik before scoring from a tight angle.
"He's good technically and physically strong, but up to now he has done nothing," said Mihajlovic.
"He has wasted six or seven years. Now, he has to make up for lost time. He could still become one of Italy's best forwards."
Lazio chalked up their first win when Antonio Candreva volleyed the first, Marco Parolo headed the second and Stefano Mauri completed the scoring from Miroslav Klose's pass in a 3-0 win over promoted Cesena.
Genoa goalkeeper Mattia Perin performed heroics to earn his team a goalless draw at Fiorentina and Atalanta won 2-1 at Cagliari.