In 2021, he won the bronze medal in the team relay event at the 2020 European Aquatics Championships held in Budapest, Hungary.

Later in the year, at the 2020 Summer Olympics, held in 2021 due to the COVID-19 pandemic and contested in Tokyo, Japan, he won a silver medal in the 10 kilometre open water swim with a time of 1:48:59.0.

[4][5] At the fifth and final leg of the World Series, held three months later in Eilat Israel, he placed fourth in the 10 kilometre open water swim with a time of 1:46:45.40 and tied Gregorio Paltrinieri of Italy for the overall highest-scoring male competitor spot.

[6] At the second leg of the 2023 FINA Open Water Tour, held in May in Golfo Aranci, Italy, Rasovszky won the 10 kilometre open water swim with a time of 1:47:17.60, sharing the podium with Domenico Acerenza of Italy (silver medalist) and Oliver Klemet of Germany (bronze medalist).

[8] Later in the month, on the second day of the tour leg in Setúbal, Portugal, he contributed to a final time of 1:24:13.10 in the 4×1500 metre mixed open water relay to help win the gold medal.