At the 2021 World Championships he won the bronze medal in still rings, sharing it in a tie with Salvatore Maresca.

[2][3] He also had won a gold medal on still rings in the Mersin leg of the 2021 FIG Artistic Gymnastics World Cup series.

In 2021 Klimentev became the Russian Champion on still rings, beating veteran Denis Ablyazin.

He made his senior international debut at the Mersin World Cup where he won gold on still rings.

He was one of the athletes representing RGF at the 2021 World Championships where he won the bronze medal on still rings.