Lautaro Martinez's first-half brace sent Inter Milan top of Serie A on Sunday with a 2-1 win over SPAL after champions Juventus were held at home by Sassuolo, while Napoli's winless run stretched to eight games.

Argentinian Martinez put Inter ahead on 16 minutes at the San Siro, and then headed in Antonio Candreva's cross to score his eighth league goal this season.

Mattia Valoti pulled a goal back, but second-from-bottom SPAL fell to their ninth defeat of the campaign.

Conte has guided Chinese-owned Inter to 12 victories in 14 league games for the first time, and they reclaimed the top spot which they had previously held until their 2-1 defeat by Juventus on October 6.

"When a team like Juventus drops points, you need to make sure that you make the most of that," said former Juve coach Conte. Lazio consolidated third place -- seven points behind Inter -- with a 3-0 win over Udinese thanks to a double from Serie A top scorer Ciro Immobile, including one from the spot, to bring his tally to 17 goals this season, and a Luis Alberto penalty.

But Napoli's winless run stretched to eight games in all competitions with a 2-1 defeat at home by Bologna, leaving last season's runners-up in seventh.

Bologna got their first win since October 27 with coach Sinisa Mihajlovic back on the bench following a bone marrow transplant as he fights leukaemia.

Despite taking a point in their Champions League game at Liverpool in midweek Carlo Ancelotti's Napoli are five points off the top four.