De Sousa qualified for the 2012 PDC World Darts Championship by winning the Western European qualifier, beating Eduardo Lopes in the final. He became the first Portuguese player to qualify for either version of the World Darts Championship. He lost 4–3 in the preliminary round to South Africa's Devon Petersen. In the rest of the year, he won the Catalonia National Championship and the Catalan Open by beating Antonio Jimenez in the final. De Sousa claimed the 2013 Soft Tip Bullshooter European Championship with a win over Franck Guillermont. He reached the final of the 2015 Catalan Open, but lost 6–1 to Carles Arola.