Australian start wasn't good enough according to thier expections, but then later after six down at 75 one of thier previous matches lower middle order hero tim David showed his magic again and through his heroic innings he put enough number on board for his team to defend against proteas, While on the other hand south African start as expected were awful even most of Australian top class bowlers wasn't part of the team, but still they get handosme number of wicket before proteas batter done damage from thier side. And thus south African got defeat in the very first match of the series against Aussies. Hope we will have much more interesting clashes in the pipeline.
It was great comeback for Australia.and you are absolutely correct that Tim David batting was most important part. To be losing six wickets with only 75 runs on board and still manage to score enough runs to defend shows his vital performance was for team. It also shows how strong Australia bowling is as they were able to take many wickets and control South Africa batsmen and we know some of their best bowlers were not playing. Bad start from South African batsmen made it almost impossible them to win and their loss in first match makes the rest of the series very interesting.