Feinberg-Mngomezulu was introduced to his most challenging assignment last weekend against the All Blacks at Ellis Park and came through the game's most testing exam.
Should he start in Cape Town in Saturday's second Lipovitan D Rugby Championship Test, he will be in more comfortable surroundings in his home environment.
It is a dream of his to play for South Africa on his home ground at Cape Town Stadium, but he hopes not to be affected by the emotions he felt at Johannesburg's Ellis Park.
"There was a lot of pressure on me. A lot of guys will say they don't see it, but I see it.
"I wanted to do well for the team and helping us get a victory, that was special [he contributed 16 points in the 31-27 win], especially when we saw the support as we drove into the stadium.
"It was amazing and I'm super proud to be a Bok."
Having impressed from the time of his Test debut against Wales in London earlier this year, Feinberg-Mngomezulu took his chance when replacing the concussed fullback Willie le Roux in their second July Test against Ireland.
As a result, coach Rassie Erasmus started him in the two Championship Tests against Australia and did well enough for Erasmus to start him against the All Blacks.
But he is not getting carried away, preferring to see what he has done so far as stepping stones.
"I'm still learning, I'm not a complete No10 yet.
"We've got a guy like Handre, a great No10, and I am still learning from him. I still see him as our No1 flyhalf, and he's a great player.
"I've got work to do still, but the results help, and they get me to progress a bit faster.
"I feel like I'm growing in the jersey, but I'm nowhere near a finished product yet. I'm 22-years-old, so I have a long way to go and a lot to learn."
Their success in the first Test was due to what they had discussed in their preparation—not switching off.
"With a side like the All Blacks, you can't afford to switch off. Credit to the boys that we didn't switch off, especially in the last two minutes with the discipline, no penalties and the tackle fight.
"It was a dogfight out there, and it wasn't our cleanest and most clinical performance.
"We didn't achieve everything we wanted...but to get a win against the All Blacks at Ellis Park when things aren't going your way, it's something else as a Springbok."