It all kicked off after the Premier League match between Manchester United and Arsenal at Old Trafford in 2004.
Tensions boiled over after the game with players from both sides brawling in the tunnel.
The game subsequently became known as the 'Battle of the Buffet', after Sir Alex Ferguson was hit in the head by a slice of pizza in the scuffles.
But who was it thrown by?
Sir Alex Ferguson discussed the matter in his autobiography, which was released in 2013.
Fabregas never discussed the topic. That was until he revealed all on Sky's 'A League of Their Own' in 2017.
James Corden was keen to get to the bottom of the mystery 13 years after the incident occurred.
"Tonight, can we finally put the case of the flying pizza to bed once and for all? Were you the culprit that threw the pizza?" He asked Fabregas.
The spotlight came down on Fabregas who, after a brief pause, shouted: "YES!"
He then explained what happened.
"All of a sudden, I heard noises (from the tunnel) and I thought what's happening? So I go out with my slice of pizza and I saw Sol Campbell, Rio Ferdinand, Martin Keown... everyone pushing each other.
"I was like, I want to get in but I don't know how to and I threw... peeew... just threw it. Once I saw it was hitting, like, who it was hitting, which I didn't mean… I apologise Sir Alex, really didn't mean to do that!"
This Arsenal fan wants his club to FAIL in the Europa League! Find out why on The Football Terrace...
Fabregas went on to confirm that the pizza hit Ferguson on the side of his head. The segment ended with the Spaniard being given a round of applause.
Fabregas was just 17 years old at the time and did not appear in the match. But he sure did make his mark at Old Trafford that day.