Gregor Townsend believes that victory over the Springboks on Saturday could surpass even this year’s Calcutta Cup win as the greatest individual achievement of his coaching career.

Scotland’s victory that day was considered an extraordinary achievement against the team then ranked number two in the world, since England had won 24 of their 25 previous matches since Australian Eddie Jones took over as their head coach.

The Springboks are meanwhile only ranked fifth in the world, just ahead of Scotland who will overhaul them if it is a home win.

However with their recent record including inflicting a rare defeat in New Zealand upon the All Blacks in September before they came within two points of completing a home and away double on the world’s number one side three weeks later, Townsend believes the South Africans are back at their fearsome best.

“Given what they have done recently, it would probably be our biggest win in the last couple of years,” he said.

“Obviously England stands out as such a memorable win. The fact they had won so many games in succession and that trophy we play for makes it even more special, but I just feel that South Africa are in the top two or three teams in the world with the way they play against the best teams in the world.

“Going to New Zealand and beating them, almost beating them a second time, showing what they were capable of last week against France as they came from behind to get a great win – that all shows they are going to be a tough team to beat.”

While victory is the only thing that really matters against a team Scotland has beaten just twice in 17 encounters in the professional era and five times in 26 encounters in all, the coach claimed that what could take it to another level would be the way a win was achieved

“Obviously the performance that day (against England) was excellent. Results and performances go together and we’d take any result which is a win. If it combines with seeing the players play at their best then that makes it even more special,” Townsend observed.

If they are to do so he would also have to break his own personal duck against their head coach Rassie Erasmus.

The pair went head-to-head on four occasions when the former Springbok flanker was in charge at Munster during Townsend’s last season in charge of Glasgow Warriors and the Irish province out-manoeuvred their opponents every time.

That has naturally encouraged a healthy respect for his opposite number, but Townsend believes the Springboks will not stray far from their core values.

“It’s number one,” he said in terms of how physical it will be.

“We get physical challenges in the Six Nations with the likes of England and France and Ireland but any coach will tell you that the biggest physical challenge is South Africa, it always has been.

“They have evolved their game since Rassie took over but they’ve not gone away from the forward pack. They select the biggest and strongest men they can find.”