Rise and Shine were handed a lifeline at Loftus Versfeld Stadium with 25 minutes remaining and trailing 2-0, but Marema failed to convert from the spot in what proved to be a turning point in the match.
The 35-year-old, who had only been introduced at half-time, slipped as he struck the ball, sending his effort over the crossbar.
Mohafe did not hesitate to act, hauling Marema off despite having just brought him on, in a move that underlined his emphasis on leadership and responsibility within the squad.
"For me, it's about leadership," Mohafe said after the match. "When you are a leader, you have to lead by example. You can't be casual in those situations. When we get that opportunity to make it 2-1, you must take it seriously."
The incident followed a similar moment just days earlier when Sundowns striker Lebogang Mothiba saw his chipped penalty saved in a narrow 1-0 win over City. However, unlike Mohafe, Sundowns head coach Miguel Cardoso opted to back his player publicly.
"He was complacent, and I felt taking him off was the best decision," said the Rise and Sine mentor.
Sundowns went on to seal a comfortable 3-0 victory, extending their lead at the top of the Betway Premiership standings to five points.
