Buoyed from scoring in Inter’s Champions League win over Feyenoord, Lautaro Martinez thought he had grabbed a 24th-minute opener in the battle between top and bottom in Serie A.
The Argentine saw his initial effort kept out by Stefano Turati before he lashed home the subsequent rebound to the delight of the home support, only for their joy to turn to frustration when the effort was chalked off for handball following a VAR review.
Monza ultimately took full advantage of that reprieve, taking a surprise lead through Samuele Birindelli just after the hour mark.
The full-back calmly slid the ball past Josep Martinez after being sent through on goal by Dany Mota’s exquisite flick.
Matters soon got worse for Simone Inzaghi’s side when Keita Balde produced a stunning effort to double Monza’s lead, cutting inside from the left flank before curling an unstoppable strike out of Martinez’s reach.
However, the title hopefuls showed great character to produce a swift response before the break, with Marko Arnautovic stooping low to head in from Denzel Dumfries’ knockdown, giving the hosts a crucial foothold ahead of the second period.
Despite pulling a goal back on the stroke of half-time, Inzaghi opted to make a double change at the break, introducing Yann Bisseck and former Monza man Carlos Augusto.
As it proved, Bisseck had a hand in Inter’s crucial leveller, laying the ball off for Hakan Calhanoglu to drill a low shot past Turati to register his 50th Serie A goal.
Augusto then vindicated his half-time arrival, sending in a dangerous cross towards the back post where Giorgos Kyriakopoulos diverted the ball goalwards under immense pressure from Martinez.
Turati did his utmost to keep the ball out, but goalline technology confirmed his efforts were in vain, handing the hosts the crucial winner to claim a fourth consecutive home league win.
While Inter piled the pressure on title rivals Napoli and Atalanta, Alessandro Nesta’s side remain rooted to the bottom of the table and 10 points adrift of safety.
Flashscore Man of the Match: Hakan Calhanoglu (Inter Milan)