Cardiff - Wales coach Warren Gatland has admitted to being wary of a resurgent South African team he says has reclaimed some of its "old identity" ahead of next year's Rugby World Cup.
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Gatland said Saturday's match at Cardiff's Millennium Stadium had the feeling of a Cup game, with the Welsh bidding for a ninth successive victory, last achieved in 1999.
Wales have seen off Scotland 21-10, edged past Australia 9-6 and overran Tonga 74-24, while the Springboks arrived in Cardiff on the back of a hard-fought 26-20 victory in Scotland last weekend following an injury-time 29-26 win over France and a 12-11 defeat by England.
"They have reclaimed some of their old identity and what they're about," Gatland said of the Boks, who now have Rassie Erasmus at the helm.
"Physicality and a strong scrum, a driving lineout and strong ball-carriers. That's why you always respect them for what they are. They have gone back to being tough and physical and have subtleties in the way they play."
Gatland played down his team's winning streak, saying it had not been used as motivation.
"What has built nicely is the momentum, the players are fully aware of what they've achieved and they can do something special and from that they know the momentum is created for the Six Nations and they can continue to build towards the World Cup," he said.
"The job is easy for us as coaches at the moment because there is a lot of motivation in the squad with players wanting to do well and fight hard for their jersey. There's also the rewards of being successful and winning and building on that momentum."
Gatland, whose sole change from the team that beat Australia was Liam Williams drafted in at fullback in place of the concussed Leigh Halfpenny, added: "It's the end of a campaign, like a Cup game - winner takes all."
During last year's autumn tour, the Springboks were drubbed 38-3 by Ireland, scraped past France and then lost to Wales after a season that saw them win just two of their six Rugby Championship matches.
But things have changed, with Erasmus crediting the players for stepping up to the plate.
"Sometimes you have to reach rock bottom to accept there are a few things wrong," said Erasmus, who named an unchanged starting side from the one that beat Scotland, with experienced lock Eben Etzebeth the sole new face on the bench after recovering from a calf injury.
"The players took responsibility, ownership and a bit of a reality check of where we were in world rugby.
"We're still ranked number five in the world... but the difference between three and six is much closer than it was maybe a year ago."
A victory on Saturday, Erasmus added, "would definitely make the tour successful, or relatively at least, because we would have liked to have won four out of four".
"We know how tough it is going to be. We have not beaten them in the last three games, and they have won eight on the trot.
"Beating a team like that will give us more confidence. If we beat them on Saturday it will mean we have won five of our last seven games, and lost two by one point and two points."
But Erasmus was under no illusion of what his team would be facing.
"In our view, Wales are definitely the most difficult opponent we will face on this tour," he said.
"Warren (Gatland) has managed to build a superb side with lots of experience, and they are playing a good, balanced game, plus they have good depth and quality in their squad.
"They put Tonga away last weekend and the previous week they defeated Australia, so we are preparing ourselves for the most difficult Test of this tour."
15 Liam Williams, 14 George North, 13 Jonathan Davies, 12 Hadleigh Parkes, 11 Josh Adams, 10 Gareth Anscombe, 9 Gareth Davies, 8 Ross Moriarty, 7 Justin Tipuric, 6 Dan Lydiate, 5 Alun Wyn Jones (captain), 4 Adam Beard, 3 Tomas Francis, 2 Ken Owens, 1 Nicky Smith
Substitutes: 16 Elliot Dee, 17 Rob Evans, 18 Dillon Lewis, 19 Cory Hill, 20 Ellis Jenkins, 21 Tomos Williams, 22 Dan Biggar, 23 Owen Watkin
15 Willie le Roux, 14 S’bu Nkosi, 13 Jesse Kriel, 12 Damian de Allende, 11 Aphiwe Dyantyi, 10 Handre Pollard, 9 Embrose Papier, 8 Duane Vermeulen, 7 Pieter-Steph du Toit, 6 Siya Kolisi (captain), 5 Franco Mostert, 4 RG Snyman, 3 Frans Malherbe, 2 Malcolm Marx, 1 Steven Kitshoff
Substitutes: 16 Bongi Mbonambi, 17 Thomas du Toit, 18 Vincent Koch, 19 Eben Etzebeth, 20 Francois Louw, 21 Ivan van Zyl, 22 Elton Jantjies, 23 Cheslin Kolbe