With a 13-game unbeaten run in Serie A spanning back to last season, Inter were certainly the heavy favourites heading into this match, but the Friulani stunned the home crowd into silence by taking an early lead.
An excellent delivery from Unai Gomez was met by the head of James Abankwah inside the box, and his effort found the back of the net to secure his first-ever goal for Udinese.
The defending Serie A champions came extremely close to equalising with their first significant foray forward, as Maduka Okoye produced an outstanding double save to deny Marcus Thuram.
But just as it looked like Inter were getting to grips with the game, the visitors shocked Cristian Chivu’s side with a second goal after only 16 minutes, as Keinan Davis’ smart pass was poked home from close-range by Jurgen Ekkelenkamp.
At this stage, it felt like Inter were going to need to create something very special to burst Udinese’s bubble.
And that’s exactly what happened after 26 minutes, when Carlos Augusto drilled a rocket of a shot into the bottom corner from distance to halve the deficit in sensational style.
The breathless nature of the first half continued past the half-hour mark, as Nicolo Barella smashed the ball past Okoye from inside the box to level the game before the interval and send the crowd wild.
The second half began in lively fashion, with Okoye needing to pull off an excellent save at his near post to prevent Henrikh Mkhitaryan from giving the Nerazzurri the lead for the first time in the match.
Inter’s intense pressure straight after the restart was soon rewarded, though, as Andy Diouf teed up Thuram perfectly on the counter, and the France international duly slotted the ball into the bottom corner from 12 yards to edge the hosts in front.
Inter were now in full flow and extended their lead midway through the second half thanks to Pio Esposito’s composed close-range strike after being set up by Piotr Zielinski.
Esposito’s second league goal of the season appeared to completely deflate their opponents, and it quickly got even worse for Kosta Runjaic’s outfit.
With just over 10 minutes to go, substitute Ange-Yoan Bonny saw his initial shot saved before slamming home the rebound to kill the game off completely and claim all three points.
Idrissa Gueye grabbed a goal back for the visitors at the start of stoppage time, but it proved to be no more than a consolation.
Following this result, Inter are up to second position behind only early pacesetters AS Roma, who they will face on Saturday in a mouthwatering Serie A clash.
Meanwhile, Udinese remain 13th with four points from their opening four league games and will aim to return to winning ways this weekend when they host Cagliari.
Flashscore Man of the Match: Marcus Thuram (Inter Milan)