Ireland coach Joe Schmidt says he will face a tough task in raising his side's morale for next weekend's Test series decider against South Africa.
The Irish looked set to be the first of the four home nations to win a series in South Africa as they led the second Test 19-3 only to lose 32-26.
"It'll take us a couple of days, probably, to get over the anguish," said the Ireland coach.
A further worry for Schmidt is centre Robbie Henshaw's knee injury.
The Leinster-bound Connacht player had to be replaced by Ian Madigan in Johannesburg and now looks to be a doubt for Saturday's decisive Test in Port Elizabeth.
Irish crumble in face of onslaught
Tries from Ruan Combrinck, Warren Whiteley, Pieter-Steph du Toit and Damian de Allende saw Ireland crumble in the face of the Springbok onslaught.
"The players are certainly disappointed," Schmidt said.
"Whenever you get the win and get the result, it's always a lot easier to bounce back even if it's a physically tiring match."
After Devin Toner's first-half try, Jamie Heaslip's touchdown after the break helped keep Ireland in apparent control at 26-10 ahead but Schmidt's side conceded three tries in the closing 16 minutes in Johannesburg.
"We missed tackles and were unlucky at times, but the result was well and truly earned by the South African ball-carriers," said the Ireland coach.
"They really did take it to us and we were not quite up the task and that is incredibly disappointing."
Jackson misses gave Springboks lifeline
Schmidt pointed to two penalty misses by otherwise impressive fly-half Paddy Jackson which would have increased Ireland's advantage when the Springboks were struggling.
"We just missed penalties before and after half-time which could have kept our confidence levels up and maybe delivered a little bit more of a blow to the South Africans," said the 50-year-old New Zealander.
"But the way they came back. They were relatively irrepressible."
Schmidt praised the performances of debutant Quinn Roux, tight-head prop Tadgh Furlong and Ulster centre Stuart Olding.
"Quinn gave us 50 minutes of real ballast in the scrums, he got around the park and he made sure that we were not losing those collisions.
"I thought Tadhg was great. It was an opportunity for him to demonstrate what he was capable of doing and I think everybody probably saw that he did just that.
"The first three tackles of Stuart were really decisive and allowed us to set our defensive line either side of him in that tackle area. That was really satisfying."