Medvedev rages in opening ATP Finals defeat to Fritz
Champion in 2020 and finalist the following year, Medvedev is in the same Ilie Nastase Group as Jannik Sinner who opens his bid for a first Finals title against Alex de Minaur later on Sunday.
American Fritz leads the group ahead of that clash following a surprisingly straightforward win in Turin over world number four Medvedev who exploded with anger during his below-par display.
Medvedev destroyed his racket after going a set down and things went from bad to worse when Fritz broke serve to take a 4-2 lead in the second set.
Medvedev was docked a penalty point for throwing his racket at a courtside microphone and during game seven of the second set he held a new racket by its head while waiting for Fritz's serve.
After the match Medvedev replied "100 percent" when asked if he was hoping for the end of the season to come along.
"I'm tired to fight against something that doesn't depend on myself," he told reporters.
"I'll see how it goes. Today actually I had my chances. I'll have them the next matches. If it doesn't work out, I go on holiday. I'm happy."
His behaviour was met with whistles from the disapproving crowd who will be hoping for a more edifying spectacle when home hero Sinner takes to the court later on Sunday.
Sinner, who lost last year's final to Novak Djokovic, tops the world rankings after a stunning season in which he claimed the Australian and US Opens -- his first Grand Slam victories -- and won five more ATP titles.
However, he has been dogged by controversy after twice testing positive for traces of the steroid clostebol in March.
He was initially cleared by the International Tennis Integrity Agency but at the end of September the World Anti-Doping Agency appealed, seeking a ban of up to two years.