The Springboks take on old foes New Zealand in the final in Paris on Saturday and while long-time friend and colleague Jacques Nienaber is head coach, this campaign has director of rugby Erasmus' influence written all over it.
Revered in South Africa as a tactical genius who has knitted together a racially diverse team into the No.1 side in the world, he is often viewed with scorn outside the country for his brash manner and at times weaponised use of social media.
There is a general view, in the northern hemisphere especially, of how the game should be played but Erasmus' Springboks do not conform to that.
After their 2019 World Cup win they were told they play "boring" rugby. Former England coach Clive Woodward said if other teams followed suit, the sport would be "dead within five years".
And yet since then many sides have tapped into what they do well, including England, who took the Springbok copybook on their run to the semi-finals this year and almost stunned South Africa in Paris last weekend.
"Where Rassie is very good is looking at the cause of the problem and saying, 'this is what we need to fix'," former Springbok assistant coach Matt Proudfoot told Sport24.
"He is driven by that process, he never sleeps looking for that advantage. Rassie has a unique ability to see what is at the core of the matter, what is the one thing that is going to make a difference."
Erasmus raises the ire of traditionalists but almost always sticks within the confines of the laws.
Outside South Africa he will perhaps be best remembered after his video critique of Australian referee Nic Berry was made public following the first Test loss to the British & Irish Lions in 2021, a series the Springboks went on to win 2-1.
And herein lies the other side of Erasmus, the streetfighter who will not lie down and go quietly into the night. He will do what he believes is right for the team, even if, as in this case, it cost him a 12-month match-day ban.
"It was very painful but I still think the video was one of the best things I could do for the Springboks at that stage," he told The Guardian. "It was never meant to go public but the words in the video asked the officials to please take us seriously before the second Test.
"I wasn't guilty of distributing the video. I was found guilty of not preventing the video from entering the public domain. The purpose was never to embarrass anybody."
Erasmus also acted as water boy against Scotland in November 2021 when he was South Africa's Director of Rugby, controversially handing out tactics while on the field.
