Torino lined up without the suspended Kamil Glik after he was sent off in last week's Derby della Mole. Milan missed the injured Riccardo Montolivo, Alexandre Pato, Kevin Constant, Daniele Bonera and Francesco Acerbi, while Kevin- Prince Boateng was suspended.
Santana almost gave the home side a dream start inside the first two minutes, cutting in from the left and firing wide.
The Rossoneri took their time to settle. Pazzini headed a Mattia De Sciglio cross over on 17 minutes. Three minutes later, Pazzini got to the by-line and pulled back for El Shaarawy to blaze over from close range.
Torino took the lead on 28 minutes after Nocerino made a terrible backpass from the centre circle. Santana latched onto the ball and ran clear, rounding Marco Amelia, who had already gone to ground, before slotting home.
Milan equalised with a touch of class five minutes before the break, when De Sciglio played Robinho in. A clever dummy deceived Valerio Di Cesare and allowed the Brazilian to poke the ball into the roof of the net.
Nocerino went from villain to hero on 53 minutes. Jean Francois-Gillet could only parry El Shaarawy's mazy run and chip, but the ball fell into Nocerino's path and the midfielder headed it in.
Bianchi fired a free-kick into the Milan wall, before a disputed goal on the hour put the game to bed.
Pazzini seemed to foul Salvatore Masiello as he ran into the area. With no whistle forthcoming, the frontman was allowed to carry on his run and drill the ball into the net from an angle. Torino were understandably furious at the decision.
Pazzini almost notched a second, but his header came back off the post.
On 76 minutes, El Shaarawy added a fourth and his 13th of the season. Gillet spilt a low cross and the 20-year-old was first to pounce.
Bianchi rose above two markers to head in a Valter Birsa cross with ten minutes to play. Birsa almost set up a grand stand finale, but the substitute saw his header saved on the line by Amelia.
Torino: Gillet; Darmian, Di Cesare, Ogbonna, Masiello; Gazzi, Basha; Cerci, (Birsa 46) Meggiorini, (Sansone 65) Bianchi, Santana (Verdi 74)
Milan: Amelia; Abate, Mexes, Yepes, De Sciglio; Nocerino, De Jong, (Ambrosini 22) Emanuelson; Robinho, Pazzini, (Bojan 81) El Shaarawy (Flamini 79)
Goals: Santana 28 (T), Robinho 40 (M), Nocerino 53 (M), Pazzini 61 (M), El Shaarawy 76 (M), Bianchi 80 (T)