Antonio Candreva's second-half equaliser earned Inter a point from a 2-2 draw at Torino, but it was not enough to lift Stefano Pioli's side above Lazio into fourth place.
Geoffrey Kondogbia gave Inter a first-half lead, but Torino hit back within five minutes to level through Daniele Baselli's header.
Afriyie Acquah fired Torino into the lead just before the hour mark, but in a topsy-turvy encounter neither side was ahead for long and Candreva's low finish hauled Inter level three minutes later.
Inter are five points adrift of the third Champions League spot, while Torino, who remain 10th, have won only two of their last 10 league matches.
Matias Fernandez's first goal for AC Milan was enough to earn them a 1-0 home win against Genoa.
The Chile international, signed on loan from Fiorentina in the summer, scored the only goal and his first of the season in the 33rd minute after latching on to Gianluca Lapadula's through-ball.
It secured Milan their fourth win in their last five league games and lifted them up one place to sixth in the table, one point behind arch rivals Inter, who drew at Torino.
Fernandez spurned several other chances and Lapadula, Lucas Ocampos, Juraj Kucka and Gerard Deulofeu all went close to increasing Milan's lead, while Genoa goalkeeper Eugenio Lamanna made a string of fine saves.
Genoa remain two places above the relegation zone, albeit 14 points clear of third-bottom Palermo.