Wednesday's results in Serie A meant that Sunday's clash between Juventus and Napoli had turned into the biggest match of the Italian football season so far.
Napoli's 4-2 comeback win over Udinese coupled with Juve's surprising draw at lowly Crotone meant the champions had a four-point advantage heading into the highly-anticipated match.
While the first half was predominantly a cagey affair, Kalidou Koulibaly's 90th-minute header handed the visitors a dramatic, massive win in the race for the title.
However, before Napoli had even entered the Juventus Stadium, their manager did something to show exactly how he feels about the reigning Italian champions.
Flanked by police cars, the Napoli team bus made its way through a sea of Juve supporters in Turin on Sunday evening, and emotions were running very high.
Rivalry runs deeper than football
The two clubs have been rivals for a very long time, given that they are two of the prime representatives with regards to the tensions between the north and south of Italy.
The Napoli bus, which contained both playing and managing staff, was barracked by opposition fans as they approached the stadium, but Maurizio Sarri was in a defiant mood.
What Sarri did to Juve fans as Napoli arrived
Sarri, who was born in Naples, has been in charge of Napoli since 2015 and developed a fine group of players, even winning the 2016-17 Serie A Coach of the Year award
To prove he wasn't intimidated by Juve fans' hostile welcoming, the 59-year-old manager responded to the insults by sticking his middle finger up at them - which you can see below.
In case you missed it, here's an image of Sarri's gesture:
Football fans react on Twitter
As you can imagine, football fans who saw the incident took to Twitter to share their thoughts, and while they were all stunned, the overall reaction was mixed.
Some have praised Sarri's passion, whilst most have criticised his lack of class, given his job and the example it sets to those who follow Napoli - check out some of the best reaction below:
In fairness, the Juve fans were giving Sarri lots of stick, but to react by swearing at his adversaries is still an incredible reaction and something he surely knew would emerge online.
Following the huge 1-0 win, Sarri's men's next assignment is a trip to Fiorentina, while leaders Juventus travel to the San Siro to battle Inter Milan.
What is YOUR opinion on Sarri throwing up a middle finger in response to Juve fans' taunts? Do YOU think he could be in trouble for his action? Have YOUR say in the comments box below!