Sousa reached several milestones in 2011. At the Challenger Tour, he won his first singles title at that level in Fürth in June. At the ATP World Tour, Sousa participated as a wildcard in the singles and doubles events in Estoril, losing in the second round of the former to Canadian Milos Raonic. He also made his first attempt at entering the main draw of a Grand Slam tournament, but fell in the qualifying rounds at the Australian Open, Wimbledon and the US Open. In October, Sousa's participation at the Sabadell Futures was his last presence in the main draw of a tournament in that category. He won three more singles and one doubles Futures titles, making his career titles at this level seven singles and nine doubles titles. Once again, Sousa was called for two dead rubbers at Davis Cup, winning over Martin Kližan from Slovakia and losing to Switzerland's Marco Chiudinelli. In October 2011, he hired Frederico Marques as a coach when he was ranked world number 220.