As relayed by Tom Dutton of the Evening Standard, the Euro-Med Seismological Centre, which monitors seismic activity across Europe, picked up some "significant ground movement" in the Neapolitan suburb of Fuorigrotta at the point Koulibaly scored.
The organisation's Facebook account posted the following snap of a seismograph and noted the point at which the centre-back fired home:
Koulibaly's last-gasp goal in the 1-0 win set up an enthralling finish to the Serie A season, as the Partenopei seek to reel Juventus in and become champions for the first time since 1990.
Thanks to the dramatic win Napoli only trail leaders Juve by a point at the top of the table with just four games remaining. The Bianconeri still have to face rivals Inter Milan and Roma away from home too.
The game was played in Turin, with the seismic activity caused by Napoli fans that hadn't made the trip celebrating back at home.
After the game social media was awash with clips of wild celebrations from the triumphant supporters. Copa 90 posted one of those:
Napoli fans have always been renowned for their fanaticism and after the goal television pictures showed a number of away supporters in tears.
As noted by the Caught Offside Twitter account, it's not the first time they've made the earth quake underneath them after scoring a goal:
As noted by Dutton, when the players returned from Juventus on Sunday night there were 10,000 supporters at the airport to meet them.
This weekend Juve go to Inter for the Derby d'Italia on Saturday night, while Napoli face a tricky trip to Fiorentina on Sunday.