He won the gold medal in the men's 200 metre butterfly event at both the 2021 FINA World Swimming Championships (25 m) held in Abu Dhabi, United Arab Emirates and the 2021 European Short Course Swimming Championships held in Kazan, Russia.

[1] In 2021, he won the silver medal in the men's 400 metre individual medley and the bronze medal in the men's 200 metre individual medley at the 2020 European Aquatics Championships held in Budapest, Hungary.

[2][3] On the first day of the 2022 European Aquatics Championships, held in Rome in August, Razzetti won the first gold medal for Italy at the Championships, placing first in the 400 metre individual medley with a time of 4:10.60.

[4][5][6] Five days later, he won the bronze medal in the 200 metre butterfly with a time of 1:55.01, finishing 3.00 seconds behind gold medalist Kristóf Milák of Hungary.

[7][8] On the seventh and final day of swimming, he won the silver medal in the 200 metre individual medley, finishing in a time of 1:57.82.