He started playing table tennis at the age of nine. In his youth, he also played soccer and handball at the national level, and basketball at the local level. In 1956, he placed second in the youth national championship. After graduating from high school, he moved to Cluj and joined the table tennis division of Progresul, where he was coached by Farkas Paneth.
In 1958 and 1959, he won the individual and doubles youth national championships.
In 1958, he became the youth European champion in the individual, doubles and mixed competitions.
In the Balkan Games, he won three gold medals (two in the doubles and one in the mixed competitions).
He participated in three editions of the Table Tennis World Championships.
A gynecologist and a doctorate holder, he defected with his wife to West Germany in 1981, leaving his two children behind. After nine months the children were allowed by the Romanian communist authorities to join their parents in Germany.
In Germany he worked first as a table tennis coach before he found a job as a doctor. He changed his name to Johann R. Wolff, and practiced medicine in Pulheim. After the Romanian Revolution of 1989, he was a visiting professor at his alma mater, the "Iuliu Hatieganu" School of Medicine and Farmacy, Cluj.
- Master of Sports (1960)
- Honored Master of Sports (1999)
Radu Negulescu, “Viitorul vine din trecut”, 2010
- "Radu Negulescu, sportivul cu un număr record de titluri la tenis de masă care a adus primul ecograf în România" (in Romanian). Adevarul. Retrieved May 29, 2014.
- "Radu Negulescu, un sportiv valoros, un medic reputat şi un cadru didactic apreciat" (in Romanian). Palestrica Mileniului III ‒ Civilizaţie şi Sport Vol. 14, no. 4, Octombrie-Decembrie 2013, 320‒324. Retrieved May 29, 2014.
- "Campionii nationali de seniori ai Romaniei - Simplu masculin - 1929 - 2014" (in Romanian). Romanian Table Tennis Federation. Retrieved May 29, 2014.
- "Viitorul vine din trecut! Vezi cine este Radu Negulescu, predecesorul lui Crişan!" (in Romanian). Retrieved May 29, 2014.