Wales hooker Ken Owens says completing a first November Tests clean sweep would be "right up there" in terms of his career achievements.
Wales host South Africa in Cardiff on Saturday needing a win to make it four from four this month.
They have already accounted for Scotland, Australia and Tonga in extending their unbeaten run to eight Tests, which represents their longest winning sequence since the 2004-05 season.
Wales have not won nine in a row since 1999, while victories over South Africa and the Wallabies during the past six months mean that for the first time, they have defeated two of the southern hemisphere super-powers in the same calendar year.
And their recent record against the Springboks - four successes from the last five meetings - augers well for Saturday's Principality Stadium clash.
"To get four from four against southern-hemisphere opposition, beating a very good Scotland side and getting a convincing win against Tonga - when we've generally struggled against a Tier Two nation - would be a huge positive," Owens said.
"It would be right up there for me."
World champions New Zealand apart - Wales have not beaten them since 1953 - their recent record against the All Blacks' Rugby Championship rivals South Africa, Australia and Argentina shows a solitary defeat from the last 10 encounters.
And it has contributed to Wales building themselves into impressive shape 10 months out from the World Cup, when the Wallabies are among their pool stage opponents.
Owens added: "I think it's the confidence you get. We've beaten South Africa, we've beaten Australia.
"When we have played them before it has been a big deal and there was a lot of pressure to beat them. It was like a World Cup final.
"But I think once you do it once, you know how to close the games out against them. You work out the intensity they play at and how clinical they are.
"I think that is where we've improved a lot as a side. We've beaten Australia for the first time in 10 years, so for us going forward it has got to be an expectancy that it becomes more of a regular thing and not just a one-off.
"I think sometimes we've been guilty of getting a lead and then just trying to hold back and defend, but southern hemisphere sides don't stop playing and back their skills."
Owens, though, is under no illusion how difficult a proposition South Africa will be on Saturday.
The Springboks arrive in Cardiff after beating France and Scotland following a controversial one-point loss to England this month. They also beat New Zealand in September.
"South Africa are going to be a different beast again on Saturday, and we know how tough it's going to be," he said.
"I think they are a different side to what we've played over the last couple of years. I think Rassie Erasmus (South Africa head coach) has done a good job out there.
"He is pretty settled with his XV and he knows how he wants to play. They are a much-improved side and beat New Zealand in New Zealand - which is no mean feat."
