Opening batsman de Kock smashed nine fours and two sixes for his 101 off 120 balls to become the third South African and fifth overall batsman to hit a century in three successive innings to take the home side past 300 after being reduced to 28 for three in the eighth over at Super Sport Park.
For India, pacer Ishant Sharma finished with 4/40 from his 10 overs, picking up his 100th ODI wicket in doing so.
On a pitch that seemed to be the flattest of the three ODIs on display so far, de Villiers had no qualms about batting first after winning the toss. Since they had already stitched up the series, the hosts rested Jacques Kallis, Dale Steyn and Morne Morkel, bringing in Henry Davids, Wayne Parnell and Imran Tahir.
The Proteas' in-form openers Hashim Amla and de Kock began in the same fashion as they did in the previous two matches, with the opening overs of Ishant and Umesh Yadav resulting in a string of boundaries. However, there was a difference this time. India would strike early, and not just once.
First up, Mohammad Shami was successful in breaking the opening stand cheaply. The first wicket yielded only 22 runs, as Amla was out pulling, caught by Yuvraj. He followed up his century in Durban with only 13 runs. Ishant then got a double break-through for his team, dismissing both Davids (1) and JP Duminy (1) in the eighth over. For the first time in three matches, the hosts were feeling the heat after being reduced to 28 for three.