AC Milan defeated Parma 1-0 to earn the Serie A provisional lead on Saturday.
Milan leads by a point from Inter Milan and Lazio, who are second and third and play on Sunday.
Midfielder Andrea Pirlo scored the only goal in the 25th minute to decide a dour match between teams who worked hard but lacked imagination in the final third of the pitch.
"We had a good game," Milan coach Massimo Allegri said. "It is always hard to come to Parma and win. We didn't have many chances, but we are leaving Parma with the victory."
Parma, meanwhile, dropped into the relegation zone.
After a slow start, Pirlo scored with a powerful long-range shot. The midfielder collected the ball unmarked in midfield, carried it forward and when no Parma player closed him down, he let fly with a shot that dipped over Parma goalkeeper Antonio Mirante.
Milan should have doubled its lead in the 37th but Mirante blocked Zlatan Ibrahimovic's first shot and then stopped his effort from the rebound.
Just before halftime Clarence Seedorf came close to adding a second. Pirlo played Luca Antonini in behind the Parma defense, he hit a low ball across the face of the goal, but Parma defender Luca Antonelli got back ahead of the Dutchman to clear the danger.
Alongside Pirlo and Seedorf in midfield, Gennaro Gattuso appeared back to his snarling best after injury disrupted his last two seasons.
"After an injury you need a bit of time to get back to your best," Gattuso said. "The knee is responding well and I just have to keep working hard with my training."
After the break neither side managed to find any rhythm. Milan tried hitting long balls forward to Ibrahimovic, but he was well marshaled by the Parma defense.
Parma meanwhile relied on the pace and trickery of Fernando Marques on the left flank, but his neat approach usually came to nothing.
"In the first half we did well and had some chances," Allegri said, "but in the second we lacked rhythm."
Also, Udinese gained its first win of the season, but needed an injury-time winner from Mehdi Benatia to beat Cesena 1-0.
