In 1976 he led the Springboks in a tough four-test series against the All Blacks. The Springboks won the first test 16–7, but lost the second 15–9. But Du Plessis and his men bounced back in the third test, winning 15–10. The Springboks took the victory in a 15–14 win over the New Zealanders in the fourth and final test. The following year he led the Springboks to victory, 45–24, over a World XV side in Pretoria. Although anti-apartheid boycotts were increasingly isolating South African sports teams, the Springboks played two matches against the South American Jaguars in 1980, made up mainly of Argentinian players. South Africa won 24–9 in Johannesburg and 18–9 in Durban. Du Plessis captained the Springboks to a 3–1 victory in 1980's home test series against the British Lions and led the team on the 1980 South Africa rugby union tour of South America in October although an injury sustained in a Currie Cup match restricted him to just two matches, including only one of the internationals against the South American Jaguars.