SIENA - Maicon scored in each half as Inter made a winning end to 2008 at the Stadio Artemio Franchi - Montepaschi Arena to become 'winter champions' with two matches to go until the second half of the Serie A season.
The Brazilian right-back netted from close range before half time, adding his second with seven minutes left to cancel out Kharja's 44th-minute equaliser and send Siena to their first defeat at home this season.
Mourinho made two changes to the team that beat Chievo 4-2 last weekend. With Stankovic out through suspension Jimenez was handed his first start of the season, while Balotelli came in for the injured Obinna.
Siena got off to a good start and Kharja forced a save from Julio Cesar with a well struck volley from the left angle of the box.
Inter soaked up a period of Bianconeri pressure and edged in front on 34 minutes when Maicon stole in at the near post to convert Balotelli's corner.
Giampaolo's men rallied and Kharja produced an equaliser on the stroke of half time, sliding home after beating Maxwell to Del Grosso's cross.
Muntari had two shots blocked by Curci and Ibrahimovic saw an effort come back off the bar as Inter upped their game after the restart.
Siena had chances of their own in the last fifteen minutes, with substitute Maccarone blazing over from close range and Ghezzal having a shot deflected off Maxwell.
In between, Inter wrapped up their eighth consecutive victory when Maxwell diverted Cordoba's shot into the path of Maicon, who lifted over the onrushing Curci to put Inter nine points clear at the top ahead of Sunday afternoon's match between second-place Juve and Atalanta in Bergamo.
Siena 1-2 Inter (HT: 1-1)
Scorers: Maicon 34, 83, Kharja 44.
Siena: 85 Curci; 2 Zuniga (11 Calaiò 90), 15 Brandao, 90 Portanova, 30 Del Grosso; 8 Vergassola, 5 Codrea, 14 Galloppa; 10 Kharja; 18 Ghezzal, 7 Frick (32 Maccarone 76).
Subs not used: 46 Manitta, 6 Barusso, 16 Moti, 21 Rossi, 23 Jarolim.
Coach: Marco Giampaolo.
Inter: 12 Julio Cesar; 13 Maicon, 2 Cordoba, 25 Samuel, 6 Maxwell; 4 Zanetti, 19 Cambiasso, 20 Muntari (77 Quaresma 73); 11 Jimenez (7 Figo 55); 45 Balotelli (18 Crespo 55), 8 Ibrahimovic.
Subs not used: 22 Orlandoni, 23 Materazzi, 26 Chivu, 33 Mancini.
Coach: José Mourinho.
Referee: Andrea De Marco (Chiavari).
Booked: Balotelli 20, Vergassola 78, Kharja 79, Samuel 81, Maicon 83, Codrea 84.