Serfontein made his test debut for the Springboks on 31 May 1980 at his home ground, Newlands in Cape Town against the touring British and Irish Lions team, captained by Bill Beaumont. He also scored his first test try in this match. The test series against the Lions, was followed with tests against the South American Jaguars, France, Ireland, New Zealand ( the so-called Rebel Tour) and England.