The Newlands contest lasted 642 balls with India registering a series-levelling victory in the shortest ever test in which there has been a winner, beating Australia's 656-ball victory over South Africa in 1932.
Jasprit Bumrah took six for 61 –- and was denied the wicket of Markram when the batsman, on 71, edged a drive and wicketkeeper KL Rahul could not hold a catch above his head.
After bowling out South Africa for 55, India were dismissed for 153, a lead of 98 runs.
Siraj was superb with his line and length in a nine over spell after South Africa had elected to bat first.
The experienced left-arm spinner would also bolster India’s frail batting that amassed only 376 runs during the innings and 32 run defeat that means the tourists now cannot achieve their major aim – a first Test series win in South Africa.
Captain Rohith Sharma, who was dismissed cheaply in both innings, said India would regroup and come back strongly despite having missed the chance to take the series.
Virat Kohli was the only batsman to test the home attack on the third day, top-scoring with 76 before being the last man out.
Earlier, KL Rahul scored 101 for India – his eighth Test century and his second in successive matches in Centurion.
Rahul, who had made a century at this very venue exactly two years ago in the 2021 Boxing Day Test match, was lauded by Rathour as India's "crisis man" for his pristine touch and strokeplay.
Kohli and Iyer went on to add 68 for the fourth wicket before both were dismissed in an inspired three-wicket spell by Rabada immediately after lunch.
India were 91 for three at lunch after being put in to bat with Nandre Burger making an immediate impact on his Test debut, taking two for 23.
South Africa have been victors in seven of India’s eight visits since the first in 1992 with one series drawn in 2010/11, but six of those successes have been by a single win margin.
India are seeking a first Test series win in South Africa and Conrad says his side are desperate to uphold their record of never having lost to the tourists on home soil.