Dean Elgar believes giving Kagiso Rabada "a rocket" helped South Africa secure a historic first Test win over India at the Wanderers.

The Proteas levelled the three-match series at 1-1 by achieving their highest successful run chase at the Johannesburg venue on a rain-affected day four.

Captain Elgar led by example with a brilliant unbeaten 96, gaining support from Rassie van der Dussen (40) and Temba Bavuma (23 not out) as South Africa chased down their target of 240 to wrap up a seven-wicket win.

Rabada took three wickets in each innings as South Africa kept the series alive following a first loss to India at SuperSport Park.

Skipper Elgar revealed paceman Rabada was fired up by some home truths.

He said: "With KG there was something that happened behind the scenes but we're not going to get into that. Sometimes KG needs a rocket. You could then almost sense the intensity and focus, he was in the zone.

"The moment he has that attitude he wants to bowl and wants to contribute, you have to use it as a captain. It was awesome to see him fire."

Elgar gave another great demonstration of his fighting spirit in a tenacious and inspiring knock, leading by example at the top of the order.

The opener said: "It's always a privilege to represent your country. I would like to think the knocks I take make me extra motivated to perform. Some would call it stupid and some would call it brave.

"The bigger picture is for us to win. We struggled to get a stable batting line-up and we had to be very patient. We've entrusted those positions to guys we feel can perform those roles and great to see them pull it off."

India's stand-in captain KL Rahul says Virat Kohli should be fit to return in the decider at Newlands after missing the second Test due to a back spasm, while Mohammed Siraj will be monitored after sustaining a hamstring injury.

He said: "Virat is feeling better already, he's been in the nets the last couple of days fielding and running around and I think he should be fine.

"Siraj is starting to feel better each day. A couple of days break might really help him. But we have quality on our bench as well, Ishant [Sharma] and Umesh [Yadav] are waiting.

"Looking forward to Cape Town. We expected every game to be competitive. A loss like this is disappointing but we've always been a team that gets hungrier after a loss."