Siraj was sublime in the morning session as India skittled their hosts for 55 on a day when 23 wickets fell and South Africa still trail their hosts by 36 runs with seven second-innings wickets remaining.
South Africa elected to bat in seamer-friendly conditions and Siraj in particular found the right line and length immediately as his nine-over spell in blistering heat paid dividends.
"I wanted to hit one area consistently. I did that and got rewarded for it," he said of his line outside the off stump.
"On these wickets, where the ball is doing so much, often bowlers tend to think, ‘let me try and bowl an outswinger darting from leg to off or get one to bend back from angle’, but you should just stick to one line.
"If you hit (good) areas, wickets will come automatically. If you try many things, you yourself can get confused."
Siraj took 2-91 in the first test in Pretoria, which was also played on a wicket with pace and bounce. He learnt from that experience.
"I realised what I missed in the last game and wanted to compensate and I executed my plans accordingly."
Siraj might have felt that having bowled the home side out for 55 in the morning session, he would spend the rest of the day watching his side bat, but an Indian collapse in which they lost their last six wickets for the addition of no runs saw them dismissed for 153.
"We had put our feet up, but this is cricket. You see both good and bad things," he said.
India are still ahead in the game, but one solid partnership for the home side could see them wrestle the initiative back, with South Africa captain Dean Elgar admitting he would be delighted to set the visitors anything over 100 to chase in the fourth innings.
"I can't predict what will happen on the second day," Siraj said. "We have to get them out for as little as possible. We are still (36) runs ahead and we have to see how many (wickets) we can get before they take the lead."
