Inter started in third however leapfrogged Lazio and head the table on goal distinction from champions Juventus.
Ante Rebic tapped home from Zlatan Ibrahimovic’s knockdown and also the Swede headed within the second before the break.
But Marcelo Brozovic volleyed in and Matias Vecino stroked home Alexis Sanchez’s cutback before Stefan de Vrij and Romelu Lukaku each scored headers.
Relive inter Milan’s thrilling comeback against AC Milan Antonio Conte’s side looked overwhelmed at half-time once a lackadaisical opening forty five minutes, however responded in sensational fashion within the period of play with four unrequited goals.
Both sides hit the woodwork during a thrilling derby, Hakan Calhanoglu smashing the post with an occasional drive and Ibrahimovic heading against the post late on, whereas Inter’s January signing Christian Eriksen rattled the crossbar with a long-range free-kick.
Milan had been in good form beneath coach Stefano Pioli, losing only one of their previous eleven league games beneath the previous inter boss, however their second-half capitulation keeps them in tenth place.
Inter are currently unbeaten in sixteen league games and host Napoli on Wed, before a vital clash against fellow title challengers Lazio next Sunday.
“It’s still very early to speak concerning something we can only dream of for currently,” Conte told Sky italia.
“We can have a dream. it is a very intense period for us coming up and then we’ll have an improved plan of our potential and our real capabilities.
“We cannot accomplish everything from one day to the next, however we are building. These guys proved they have great strength and guts today.”
Earlier on Sunday, Simone Inzaghi’s Lazio sidewhoowed their credentials by extending their unbeaten run to eighteen games with a slender 1-0 win at Parma – former Manchester city striker Felipe Caicedo scoring the winner.