Springbok prop Steven Kitshoff told the South African media on Sunday that "it felt like we were chasing ghosts for 20 minutes" after a 35-20 Rugby Championship mauling in New Zealand.
A brilliant start by the All Blacks saw them score two tries and 17 points in as many minutes against the error-strewn Rugby World Cup title-holders in Auckland on Saturday.
South Africa are renowned as set-piece maestros, but all they did in the opening quarter was concede penalties, miss tackles, and lose lineout, breakdown and aerial battles.
The Sunday Times quoted veteran Kitshoff saying "the All Blacks pride themselves on the way they attack, but to attack you need a good set piece.
"There are a lot of lessons for us, especially when it comes to set-piece defence," said the champion at the last World Cup, in Japan four years ago.
"This is a huge wake-up call for us," he added ahead of their final Championship match, against Argentina in Johannesburg on July 29.
With New Zealand holding a four-point lead going into a final-round match against struggling Australia, the clash of the second-placed Springboks and the Pumas is set to decide second spot.
Head coach Jacques Nienaber echoed Kitshoff, telling the Times "defensively we were bad, we must have missed six or seven tackles in the first five minutes".
"We (also) struggled under the high ball, and those are two of our strongest areas. We just have to improve in those areas."
MISSED CHANCES
Nienaber, who moves to Irish outfit Leinster after the September 8-October 28 World Cup in France, also highlighted the failure of the Springboks to take chances.
"Tonight (Saturday), Cheslin (Kolbe) was called for a knock-on, Eben (Etzebeth) was over the line but held up.
"When you play the All Blacks you do not get many chances, and those you do get, you have to take."
Nienaber hailed lock Etzebeth, standing in as captain for injured Siya Kolisi, who played despite the midweek death in Cape Town of his father Harry after a long battle with cancer.
"He is a brilliant guy and (his decision to stay in New Zealand) shows how much the Springboks mean to him.
"It is quite personal. I am not walking in his shoes. I do not know where he is at mentally. All we could do from our side was support him as much as we could.
"We had another player who is going through the same thing," added the coach, referring to scrum-half Jaden Hendrikse grieving the recent death of his father Brian.
A shoulder injury prevented Hendrikse being considered for the Auckland test, but he is expected to be available for World Cup selection, with the 33-man squad to be named on August 8.
After the Championship, South Africa will play Argentina in Buenos Aires, Wales in Cardiff and New Zealand in London in warm-up matches ahead of the World Cup.
South Africa are in Pool B with Scotland, Romania, Ireland, currently the top ranked test nation, and Tonga and the section winners and runners-up qualify for the quarterfinals.
Should the reigning world champions reach the last eight, they are likely to face second-ranked France or New Zealand.