The 63rd minute settled it. Thapelo Maseko took a low cross from substitute Tshepang Moremi, steadied the ball, and drove it into the bottom corner of the net at Estadio Monterrey. One touch, one finish, and South Africa held a lead they would not surrender.
A solitary second-half strike from Thapelo Maseko proved enough to separate the sides as South Africa finished second in Group A and booked their place in the round of 32.
For a country that had never before survived a World Cup group, the moment carried the weight of history.
How it was decided
The winner belonged to two men.
The assist came from Moremi's very first touch of the World Cup; introduced moments earlier as Hugo Broos searched for greater attacking energy, he immediately changed the tempo with his pace and directness before creating the breakthrough.
Maseko did the rest, and the finish carried its own footnote:
it was Bafana's first non-penalty goal at the World Cup since 2010.
It had not come easily. Maseko endured a difficult night before the decisive strike, spurning chances that left Broos exasperated on the touchline.
After wasting several opportunities throughout the contest, he finally lit up households across South Africa in the 63rd minute when he calmly controlled and finished the low cross.
The match itself turned on preparation and heat.
The scorching Monterrey conditions appeared to favour the Africans, with South Korea visibly fading physically as the half progressed.
South Korea, meanwhile, gambled on rest.
They made the interesting call to leave Son Heung-min on the bench, and this proved fatal.
He came on after the interval, but the game had already tilted. In stoppage time
Ronwen Williams was called upon for his most pressing save, clutching a glancing header to protect the advantage.
The trajectory
Broos had reshaped the side for the occasion.
In what could have been his final match in charge, he made three changes to the team that drew with the Czech Republic; Relebohile Mofokeng and Evidence Makgopa were handed starts, while Sphephelo Sithole replaced the suspended Teboho Mokoena.
The reward was tangible.
Bafana will face Canada in the next round thanks to Maseko's second-half strike, and a renewed sense of energy and attacking flair that had been missing against Mexico and Czechia.
Set against the wider story, the significance sharpens.
For a nation that waited more than two decades to return to the World Cup through qualification rather than host-nation status, this instantly became one of the most important results in modern South African sport.
Maseko, a winger who has spent much of his career in the domestic game, was the man who delivered it, and the recognition that followed marked him out among his countrymen.
One touch. A first for a nation. His name now sits where none had before.
