The Toulouse flyhalf spoke glowingly about his opposite number for Saturday's massive clash in Paris, noting the impact the young Bok has already made on the Test scene - and the effect he appears to have on the players around him.
"He's very good; I watched him play during the Rugby Championship," Ntamack said.
"He's an additional weapon and also brings out the best in exceptional players like Cheslin Kolbe and Kurt-Lee Arendse. We'll have to keep him and the others contained... Physically, it will be a very tough challenge."
Ntamack says France have learned to expect the unexpected from Rassie Erasmus and his Boks, and they've spent weeks ensuring they are better prepared for it this time around.
"We expect all sorts of innovations from the Springboks, but since we've all been together at the CNR, we've been trying to study them as much as possible so we're not caught off guard."
With aerial contests expected to be a defining part of the match, Les Bleus have been training heavily under the high ball - an area where South Africa traditionally dominate. Ntamack says France know they must meet that challenge head-on.
"We're trying to improve and find new ways to win aerial balls, an area that's all the more important when we're playing the Springboks, who excel in the air," he added.
"Being good under the high ball allows us to absorb the pressure and turn it around. It's an attacking weapon."
Ntamack was not part of the team that lost by one point to the Boks in the World Cup quarter-finals two years ago, but he didn't shy away from the fact that the result impacted the French players
"I wasn't part of that World Cup quarter-final squad, but the trauma affected more than just the 23 players on the team sheet.
"Since then, all that has passed, and now we're focused on Saturday night's match."
Ntamack was also asked about his combination with Racing 92's Nolann Le Garrec, who will don the number nine jersey in the absence of Antoine Dupont.
"We've known each other for quite some time. We've been together a lot at training camps in Marcoussis, so we've developed a good understanding," Ntamack said.
"We just hope to lead the team as well as possible to help them beat South Africa at the Stade de France."
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One of the most anticipated Test matches of the year is set to take place between France and South Africa at Stade de France on Saturday.
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