Warren Gatland's men ran the Springboks close during this summer's second Test in Pretoria and Evans feels now is the time for them to record their second-ever victory over South Africa.
"South Africa is the best chance of a win," Evans said on BBC Wales' Scrum V.
"Australia are probably the most innovative and New Zealand are going to be a handful."
Evans believes an uncertainty over style and a large degree of fatigue will prevent the Boks from being at their best when they run out at the Millennium Stadium on November 8.
"South Africa are still unsure what sort of game they want to play," said Evans.
"Also, a lot of their players are looking tired. Butch James has played two years of solid rugby."