India beat South Africa by six wickets and ended the latter's 17-match winning streak at home.
This is also India's first ODI win in Durban.
South Africa had posted 269/8 in 50 overs for India to chase, which the visitors touched with 6 wickets in hand.
All thanks to Indian skipper Virat Kohli's 33rd hundred and Ajinkya Rahane's classy half-century that has scripted a sensational win over South Africa in the first ODI of a six-match series.
The captain started well by punishing pacer Bhuvneshwar Kumar for three consecutive boundaries as the second wicket stand started flourishing to 83/1 until Chahal struck with the wicket of de Kock, trapped in front before jolting the hosts with the wicket of Aiden Markram (9 off 21), thanks to a brilliant running catch from Hardik Pandya.
Skipper Faf du Plessis' helped South Africa recover from a minor collapse as the opener of the six-match One-day International series at Kingsmead here. He survived a few close chances before reaching his century off a single from Bhuvneshwar Kumar, and later in the company of Andile Phehlukwayo (27 not out off 33; 4X1, 6X1) raised a 56-run seventh wicket stand.
Coming in at No.3, du Plessis (120 off 112 balls; 4X11, 6X2) steered the South African ship with three vital half-century partnerships even as the Indian wrist spin duo of chinaman Kuldeep Yadav (3/34) and leggie Yuzvendra Chahal (2/45) shared five wickets between them to rip through the top order.