The Nerazzurri were coming off a poor run of form and the moral-boosting win against high-quality opposition will be more than welcomed by Simone Inzaghi.
The goal came towards the end of the first half from Hakan Calhanoglu with one of his trademark strikes from distance.
Calhanoglu makes the headlines
The game started at breakneck speed and one of the first major flashpoints came in the 22nd minute when Inter wanted a penalty. Joaquin Correa was attempting to bring the ball down in the box when Eric Garcia arrived on the scene and handled the ball.
The monitor was checked and it was a clear handball, but then an offside in the build-up was spotted and play continued. Correa later rounded Marc-Andre Ter Stegen but he was clearly offside.
Inter did get the lead just before half time though as Calhanoglu hit a superb low drive into the bottom corner from the edge of the box, sparking wild celebrations in the process.
Barcelona had the majority of the ball in the second half as was to be expected and they did find the back of the net when Pedri poked in after Andre Onana flapped at a cross. Another VAR check showed that the ball brushed Ansu Fati’s hand on the way through and the goal was ruled out.
The victory means that Inter move to six points and are in second place in the group. That is key as they are now three points ahead of Barcelona and in the driving seat to get through to the Round of 16.