Boks played on England's altitude issue
England's approach to playing at altitude has come under scrutiny after South Africa's Faf de Klerk revealed the Springboks sensed they were vulnerable due to being based at sea level.
De Klerk was the ringmaster as Eddie Jones' men allowed a 21-point lead slide into a 42-39 loss.
Jones has located his squad in Umhlanga by the Indian Ocean rather than on the Highveld, even though the first and second Tests are staged at altitude.
"We knew they were based in Durban and that coming from the UK the altitude was going to be a factor," De Klerk said.
"I think the altitude plays a part. England made a few errors they don't usually make and that played into our hands."
Hooker Jamie George admits that the thin air at the sport's highest venue, which stands over a mile above sea level, took its toll.
"It was tough after 20 minutes. It really did kick in. After 20 to 30 minutes it definitely hit us quite hard," George said.