Hmm, interesting: a short while ago, the 23-year-old Brazilian qualifier (& 2018 USO junior champion), Thiago Wild, despatched Medvedev (2) in five sets (7-6(5) 6-7(6) 2-6 6-3 6-4) in 4¼ hours.
Slightly off topic, it would seem that he took a leaf out of Zverev's book a couple of years ago, when, according to Wiki, he "was investigated by Brazilian police for physical and emotional abuse towards ex-girlfriend Thayane Lima for which he received a restraining order." He subsequently denied the charges & initiated a defamation lawsuit.