Hazard scored the title-clinching goal to crown the Foxes Premier League champions as Tottenham Hotspur's two-goal lead against Chelsea was cancelled out in May 2016.
It was a first Premier League title for both Ranieri and Leicester, who were 5,000-1 shots to win the division at the beginning of the season.
A couple of years on, Ranieri, who managed Chelsea before José Mourinho was first appointed manager in 2004, still feels indebted to the Belgian star.
When Hazard's effort rippled the top bins on that memorable Monday night, Ranieri was watching from the comfort of his own house.
I was in the armchair at the time. Well, until Eden Hazard's goal went in and the final whistle was blown and then I was on the ceiling!