The volatile Russian smashed his racquet six times after going 2-0 down in the second set en route to his unprecedented 49-minute capitulation to Matteo Berrettini on Wednesday.
The 30-year-old hurled his racquet into the clay time and again after picking it up, and chucked it to the back of the court, cheered on by spectators, before finally smashing it to smithereens with one last mighty crack against the ground and then placing it calmly in a bin.
Medvedev, who'd been in fine form on the US hard-court swing, finished his nightmarish afternoon with 28 unforced errors and five double faults to suffer his first 'double-bagel' defeat in 626 career matches.
It was only the fifth time that a top-10 player had lost 6-0 6-0 since the ATP rankings began in 1973 -- and the first time in a decade.Â
But for wildcard Berrettini, there was nothing but delight following an injury-plagued period for the former Wimbledon finalist as he described the win as "one of the best performances" of his life.
It was the stand-out result of another eventful day in which fourth seed Lorenzo Musetti's shock 7-6 (8-6) 7-5 defeat to local Monegasque hero Valentin Vacherot spelt promising news for Australia's familiar lone survivor Alex de Minaur.
Fifth-seed de Minaur had been lined up as a potential quarter-final opponent for Musetti in what had promised to be a re-run of their semi-final last year which the Italian won.
The draw has opened up a little for 'Demon' should he get past qualifier Alexander Blockx in Thursday's last-16 clash, although the Belgian world No.91 may fancy another belated gift after outplaying 10th seed Flavio Cobolli 6-3 6-3 to celebrate the biggest win of his career on his 21st birthday.
Earlier, Alexander Zverev rallied from 0-4 and 2-5 down in the deciding set against Chilean qualifier Cristian Garin to make it to the last-16 with a 4-6 6-4 7-5 victory.
The German will next meet Belgian Zizou Bergs, who defeated Andrey Rublev 6-4 6-1.
Brazilian Joao Fonseca continued his ascent by becoming the youngest to reach the last-16 in the Masters since Rafael Nadal and Richard Gasquet 21 years earlier.
The 19-year-old defeated Frenchman Arthur Rinderknech 7-5 5-6 6-3 to set up a clash against Berrettini.