Cape Town - Kagiso Rabada's strike in the second last over of the day has given the Proteas confidence of restricting England to a modest first innings score in the fourth Test match at Old Trafford.
The hosts finished on 260/6 at stumps on day one, after winning the toss and electing to bat.
Fast bowler, Duanne Olivier, says the attack is pleased with the performance, and have set the target of dismissing the last remaining four wickets as cheaply as possible.
"I felt like we bowled really well," he said at stumps on Friday.
"The last session with the new ball we had a few play and misses which was unlucky but credit to them, they batted well in that situation. Getting the wicket, KG (Rabada) bowling Stokes, that puts us in a good position. We need four more wickets and it will be important to do the basics (Saturday) like we did today.
"They didn't run away with the game," he added.
"Yes, they batted well in the end, Stokes (58) and Bairstow (33 not out) got a partnership but I feel like it's even at the end. It swayed our way a bit because we only need to get four more wickets tomorrow."
The 25-year-old says he was prepared for the late call-up following the injuries to Chris Morris and Vernon Philander, and has been preparing and practising like he was going to play throughout the week.
He recovered from a poor 13-run over - which he attributed to nerves - to come back with the crucial wicket of Joe Root for 52 to add to Keaton Jennings' (17) scalp.
"I knew what I needed to do," he said of his attitude after the big over.
"Coming back, that first over didn't go according to plan. It was disappointing for myself and my performance, and for the team because we put a lot of pressure on them. To give it away like that was disappointing. He (Du Plessis) told me to back my skills, we know what we need to do, we know what we are worth and to do the basics right.
"With the new ball, the ball was nipping quite a bit," he explained.
"I'm still fairly new, I had a lot of nerves, and I bowled a bit too wide. I settled in the older the ball got and I bowled a lot straighter which made it difficult to score with the right fields."