South Africa beat New Zealand 26-10 on Saturday in the Rugby Championship opener in Mbombela, adding to the woes of the embattled All Blacks.
New Zealand flew to South Africa having lost four of their previous five matches amid calls for coach Ian Foster and captain Sam Cane to be sacked.
Foster and Cane will now know that another defeat to the arch foes when the teams clash again next Saturday in Johannesburg will almost certainly spell the end for both of them.
The ferocity of the Springboks constantly unsettled the All Blacks, who were lucky to trail only 10-3 at half-time having been outplayed in the opening 40 minutes.
New Zealand did win more possession in the second half but basic errors cost them and their only try, from replacement loose forward Shannon Frizell, arrived when South Africa were reduced to 14 men.
Wing Kurt-Lee Arendse, scorer of the first South African try, was red-carded on 75 minutes after fouling airborne fly-half Beauden Barrett.
"It was exactly what we wanted. We wanted to be upfront," said South Africa captain and flanker Siya Kolisi.
"Our high balls were good. We did all the things we wanted to do. We made the tackles, we know how dangerous they can be. They have a couple of players who can break the game open at any time."
Under-fire Cane said: "A lot of credit has to go to the Springboks, especially the way they played in the first half. They threw a heck of a lot at us. We did well to absorb that but it took a lot out of us.
"They are extremely good at applying pressure. Their kicking game was good, they probably won that as well."
Hooker Malcolm Marx was warmly greeted by the sell-out 42,367 crowd in recognition of him winning his 50th cap when he ran on to the field ahead of his teammates in the northeastern city.
- De Klerk knocked out -
There was a dramatic start to the southern hemisphere championship opener with Springboks scrum-half Faf de Klerk knocked out after his head struck the knee of All Blacks wing Caleb Clarke.
De Klerk had to be stretchered off, but received lengthy applause when he appeared on the sideline midway through the opening half having failed a head injury assessment test.
Inexperienced Jaden Hendrikse, who debuted in a home series against Wales last month, replaced De Klerk just 43 seconds into the match.
Fired-up South Africa dominated early possession and territory and went ahead on eight minutes when Arendse scored his first try for the reigning world champions in only his second appearance.
The New Zealand defence failed to grasp a lofted kick from fly-half Handre Pollard and centre Lukhanyo Am fed Arendse, who raced over the tryline.
Unpredictable goal-kicker Pollard did well to convert from the touchline and increased the lead to 10 points on 22 minutes by slotting a close-range penalty.
There was a sudden change of momentum as half-time approached with New Zealand, helped by a steadier scrum, awarded four penalties in quick succession.
Full-back Jordie Barrett, one of three brothers in the All Blacks starting line-up, converted one of the penalties on 36 minutes to narrow the gap to seven points and it remained 10-3 until half-time.
In the build-up to the match, Springboks coach Jacques Nienaber had emphasised the need to translate dominance into points and will have been disappointed that his team were only seven points in front.
He would have been thrilled with the performance of Marx, though, as the Japan-based front-rower won several turnovers and figured constantly in assaults on the All Blacks.
In the second half, Pollard kicked two penalties and a drop goal to give the home team a 19-3 lead before both teams scored late tries.
Frizell dived over in the corner and fellow substitute Richie Mo'unga converted, then replacement back Willie le Roux scored beside the post and Pollard converted for a personal tally of 16 points.