Inter Milan late Saturday snatched a 2-1 win over solid hosts Siena as Brazil defender Douglas Maicon scored a brace to give his side a nine-point lead over second-place Juventus, dpa reported.
Inter now have 42 points from 17 games as the Serie A gears up for a three-week winter break. Juventus may move to within six points of Inter if on Sunday they win away to tough Bergamo hosts Atalanta.
Maicon put the champions ahead before Frenchman Houssine Kharja levelled for the Tuscany hosts late into the first half and secured the Serie A champions' win with seven minutes left.
Kharja came close in the first minute with a fast drive from an angled position that forced a good deflection from Brazilian Julio Cesar.
Siena produced a massive pressing in midfield that effectively stifled Inter's manoeuvring, but failed to create truly telling changes throughout the first half hour and had their dithering defence to blame when they fell behind on a corner kick on 34 minutes.
Maicon easily deflected home the low ball that Mario Balotelli sent in the goal area as no Siena defender stood by the closest post and goalkeeper Gianluca Curci failed to intervene.
Kharja scored his winning header on 44 minutes, having the best of Brazilian Maxwell as he connected with a good cross that Cristiano Del Grosso centred from the left flank.
As Inter sought the three points and stepped up their tempo after the break, Curci had to block a spurt from Swedish star Zlatan Ibrahimovic and had to thank his defenders for stopping a drive from Sulley Muntari.
Inter had further chances through a wide drive from Muntari, while Ibra's swerving shot on 59 minutes shook the bar above a seemingly beaten Curci.
The just fielded Massimo Maccarone squandered a mouthwatering chance for Siena on 77 minutes, firing high from close range due to the pressure from Ramiro Cordoba.
Maicon's winning goal was a deft touch past the onrushing Curci, but left Siena complaining about a possible offside from the defender off a Maxwell feed.
Earlier Saturday action saw Lazio edge visiting Palermo 1-0 to end a bad run that saw them notch two meagre points from five games.
Veteran Tommaso Rocchi came on in the second half to score the winner deflecting home a low cross from Frenchman Mourad Meghni. Lazio moved on to sixth place on 27 points.