It was a wild game at San Siro, as Torino took a 2-0 lead and seemed destined for a shock victory, only for Inter to turn it around and win 4-2.
The Granata lost star striker Andrea Belotti in the warm-up and Simone Verdi soon after, but Simone Zaza still gave them a deserved lead on the counter-attack.
VAR was used to give Cristian Ansaldi a penalty for 2-0, but that woke the Nerazzurri up for a furious comeback.
Within a few minutes, it was 2-2 through Alexis Sanchez and Romelu Lukaku, then VAR intervened again for a Lukaku penalty, as Achraf Hakimi was not offside following a second Nicolas Nkoulou touch.
Lautaro Martinez completed the rout on a Lukaku assist, meaning Torino have thrown away 14 points from leading situations this season.