With Olivier Giroud suspended and Noah Okafor injured, Stefano Pioli called Camarda up to his matchday squad for the visit of the Viola, where Luka Jovic led the line.
Milan drew first blood on the stroke of half time through a Theo Hernandez penalty, but Jovic failed to make the most of his opportunity and was hooked on the 83-minute mark for Camarda.
At 15 years and 260 days old, Camarda broke the previous record for the youngest Serie A player by 14 days, previously held by Bologna defender Wisdom Amey since May 2021.
Camarda - who was born 10 months after Milan's most recent Champions League triumph in 2007 - joined the Rossoneri setup in 2015 and reportedly racked up an unbelievable 485 goals in 89 games for the academy before being invited to train with the Under-19s at the age of 14.
The 6ft 1in striker is already a six-cap international for Italy's Under-17s and has scored four times for his nation at that level, while he has seven goals and two assists in 13 matches for Milan's Under-19s so far this term.
Milan's slender win over Fiorentina moved them above Napoli into third place in the Serie A table with 26 points from 13 games, and Pioli's side are next in action against Borussia Dortmund in the Champions League on Tuesday night.