In April 2009, Ngasa was invited for a trial with English Premier League side West Ham United.
In July 2011, Ngassa went on trial with Seattle Sounders FC of Major League Soccer, and came on as a substitute against Manchester United in a friendly match.
[5] In 2015, Ngasa signed a four-year contract with Free State Stars, a South African-based club.
[6] He is one of the top scorers of 2014 CAF champions league with two hat tricks making a totality of six goals.
Ngassa is among of talented players in Tanzania who impressed many coaches and scouts around the world, among the famous coaches who was impressed by his talent was Gianfranco Zola, the former Chelsea and Italy national team player, who was working as the manager of West Ham United F.C.