The hosts went into the game having lost their last seven meetings with the Ligue 1 champions and that run only ever looked like being extended as Monaco looked sloppy in defence throughout.
It took the visitors just three and a half minutes to find the opener, Cavani turning home Neymar's cross-cum-shot at the far post.
The strike was initially disallowed, only for VAR to overturn that decision and get PSG off to a flier.
The video assistant was required again seven minutes later as Cavani slid home the loose ball after Moussa Diaby had attempted to round Diego Benaglio, with it once again overturning the original decision to put PSG two goals to the good.
The game was as good as won at that point and things got worse for the home side as Nacer Chadli was forced off through injury.
His replacement, Jordi Mboula, had Monaco's best chance, but he could only side-foot over at the far post with the goal gaping.
Kylian Mbappe saw a one-on-one well kept out as the break approached, whilst Julian Draxler's stoppage-time effort was chalked off for offside.
The PSG dominance continued after the break as it took Cavani just eight minutes to complete his hat-trick as he tapped home at the far post from a Diaby centre.
A clumsy challenge from Djibril Sidibe on Mbappe gift wrapped PSG their fifth as Neymar did the honours from the spot, with the World Cup winner denied the goal of the game late on by the offside flag.
The starlet left Benaglio for dead with a dummy before slotting home form a tight angle, but the linesman cut short his celebrations.
The legwork had already been done, though, with PSG recording their 13th straight league win and reinforcing their position at the top of the table, with Monaco avoiding propping up the French top flight only thanks to goal difference.
November 11, 2018