Born in São Leopoldo, Zwetsch began competing on tour in the late 1980s.

[1][2] Zwetsch represented Brazil at the 1995 Pan American Games, where he partnered Gustavo Kuerten in the doubles event.

[3] Now a tennis coach, Zwetsch is a long serving captain of the Brazil Davis Cup team, which he has led since 2010.

During his tenure he has twice captained Brazil in the World Group, the first time in 2013, then again in 2015 following a playoff win over Spain in São Paulo the year before.

[4] He has previously been the individual coach of top 50 players Thomaz Bellucci and Flávio Saretta.