Mamelodi Sundowns’ Tau was an instant hit netting his side’s second goal a minute after replacing Tokelo Rantie in the game played at the Godwill Akpabio Stadium, Uyo.
The victory takes Stuart Baxter’s men to second place in Group E – ahead the Super Eagles and Seychelles who were pummelled 5-1 by Libya in Tripoli.
But the 23-year-old forward is eager to guard against complacency and claimed his team are far from perfect.
''It’s a massive win with the new coach and a new group,'' Tau told media.
''We still have a long way because we are still trying to get ideas from the coach on how wants us to play.
''We have always looked forward to defeat Nigeria and our country will be happy that it happened today.''
South Africa face Zambia in a friendly game on Tuesday at Moruleng Stadium, before assembling in August for their crunch Fifa World Cup qualifier against Cape Verde Island.
And on March 27, 2018, they host Libya as they push for a place in Cameroon after missing out of Gabon 2017 Afcon.