He reached his first ATP final as a lucky loser at the
2020 Argentina Open after the withdrawal of top seed
Diego Schwartzman in the semifinals but lost to
Casper Ruud in the championship match. He had never reached a tour-level quarterfinal prior to this tournament, becoming only the third player from Portugal in the
Open Era to reach a tour-level final. In April 2023, using a qualification wildcard, Sousa qualified into the main draw for his last appearance at an ATP Tour event and his home tournament, the
2023 Estoril Open. He also announced his retirement from professional tennis, the
2023 Lisboa Belém Open Challenger being his final event. He retired on 6 October 2023. In 2024, Sousa started coaching
Henrique Rocha. ==ATP career finals==