New Zealand Vs South Africa: The Kiwis Take Wing

Where did South Africa lose the match to New Zealand? Was it the strong nerves under pressure and the magnificent six hit by Grant Elliott in the nail-biting climax, the run-out opportunity and some half chances that went unused, or the fact that rain disrupted the match at a time when AB de Villiers and Faf du Plessis had the bowlers at their mercy and threatened to take to score to 350-plus?