MILAN, Italy - Zlatan Ibrahimovic and Ronaldinho each scored twice Sunday in Serie A wins for Inter Milan and AC Milan.
Inter beat AS Roma 4-0 to move two points clear atop the Serie A standings, and Milan defeated 10-man Sampdoria 3-0.
Inter improved to 16 points, two ahead of Udinese, Catania and Napoli. Milan is in a four-way tie with 13 points, and Roma has seven.
With Christian Panucci and Philippe Mexes both suspended, Roma's makeshift central defensive pair of Simone Loria and Juan struggled to contain Ibrahimovic, who scored at the beginning of each half.
Dejan Stankovic and surprise starter Victor Obinna added goals for Inter in the 54th and 56th minutes at the Stadio Olimpico.
"Inter was devastating tonight. Every time they had the ball deep in our area, they scored. It's one of the strongest teams in Europe and merits the utmost respect," said Roma captain Francesco Totti, who made his first league start since undergoing knee surgery in April.
Milan had a man advantage from the 55th minute after Sampdoria defender Stefano Lucchini received a second yellow card for a hand ball inside the area. Ronaldinho converted the penalty and added another goal in the 66th on a give-and-go with Brazil teammate Kaka.
"Ronaldinho is working to improve his form and is again becoming a very important player," Milan coach Carlo Ancelotti said. "The game was clearly conditioned by the fact that they played with 10 men. Early on, we had the same difficulty holding onto the ball as in previous games, but the difference this time was that we kept our equilibrium and didn't fall behind."
Sampdoria came close to scoring in the 21st minute as Gennaro Delvecchio sent a bicycle kick just wide.
With the entry of Kaka at the start of the second half, Milan became more aggressive and began to take control of the game even before Sampdoria were reduced to 10 men. Kaka had been rested for the first half after recently arriving from Brazil, where he had been on international duty.
Filippo Inzaghi scored his first goal of the season in the 90th to make it 3-0.
Bologna, which had lost five straight after winning its first game of the season, stunned Lazio 3-1 with two goals from Marco Di Vaio. Bologna had scored only three goals in its first six games, but collected three in 26 minutes against Lazio, the co-league leaders coming into the weekend games.
"We started playing after 16 minutes, but at that point we were already down 2-0," Lazio coach Delio Rossi lamented. "We didn't play well, above all in the first half. It was an uphill battle the whole way."
The victory may have saved Bologna coach Daniele Arrigoni his job. Italian newspapers had reported during the week that he was likely to be fired if Bologna lost its sixth straight match.
After the first goal, the Bologna players demonstrated their support, running to the bench to hug Arrigoni.
In the Sicilian derby, Catania defeated visiting Palermo 2-0 with two second-half goals. Catania has won its last six matches in Serie A and cup games at its Massimino stadium.
Cagliari needed a goal in the 88th from Robert Acquafresca to defeat Torino for its first victory of the new season.
Also Sunday, Chievo Verona drew 1-1 with Atalanta; Genoa beat Siena 1-0; and Lecce drew 2-2 with Udinese.
On Saturday, Napoli defeated Juventus 2-1 and Fiorentina beat Reggina 3-0.