[8] On February 17, 2019, he won his first title with Panathinaikos, after beating PAOK[9] in the 2019 Greek Cup Final, which was held at Heraklion Indoor Sports Arena.

On July 19, 2022, Papapetrou signed a two-year contract with Serbian powerhouse Partizan, under coach Željko Obradović.

Partizan ended the 2022–23 season by lifting the ABA League championship trophy, after a victorious 3–2 series against Crvena zvezda in the finals.

[14] As a member of the Greek junior national teams, Papapetrou played at the 2009 FIBA Europe Under-16 Championship.

He also played at the 2010 FIBA Europe Under-16 Championship, where he averaged 11.4 points, 4.6 rebounds, and 2.3 assists, in 32.1 minutes per game.

[15] He also played at the 2013 FIBA Europe Under-20 Championship, where he averaged 15.9 points, 5.3 rebounds, and 1.6 assists, in 33.0 minutes per game.

He was selected to Greece's 12 man roster for the 2016 Turin FIBA World Olympic Qualifying Tournament.