Williamson's centuries at Dunedin (130) and Hamilton (176) bookended his lowest test aggregate - three - during the Proteas' dissection of the Black Caps inside three days at Wellington.
However, he was anointed by the tourists' coach and captain as one of the greatest batsmen they have encountered.
"They [the South African team] see him as as good of a player as they have ever played against," coach Russell Domingo said.
"Players in this team have played against the likes of Ricky Ponting and Steve Smith, and with Jacques Kallis. He's up there, there's no doubt about it. To have 17 test centuries in 61 tests is phenomenal.
"It's also the way he goes about his business. He's a quiet, unassuming guy. One or two players are happy when he gets tons because they're such good mates with him. New Zealand are fortunate to have him."
The gentlemanly but competitive conduct between Williamson and South African skipper Faf du Plessis was a highlight of the series. Unlike the poisonous barbs directed between the captains in the India-Australia series, Du Plessis reserved special praise for his opposite.
"New Zealand played some good cricket, especially Kane," he said. "I would like to congratulate him on two hundreds out of three games. If we can get Kane, that's half the battle."
The feeling is reciprocated in Williamson's team. New Zealand has seldom had world-class cricketers - fingers might be required to count them, but certainly not all toes. The captain's selflessness is celebrated as much as his ability.
Hence, Williamson shoulders arms to requests that he gush about his performances, especially after equalling Martin Crowe's New Zealand record of 17 test centuries in seven less innings.
"Hogan [Crowe] is a special player in our country; our best batsman and extremely stylish," he said.
"He set the benchmark, and I believe will continue to be the benchmark, but personally they [centuries] are not big focuses of mine. I'd rather focus on what I need to do at the time, and try to do it for as long as I can, whether that's a hundred, or less, or maybe more.
"That'd be the most pleasing thing for me in this match, not so much the number [17] but the one in this game which meant getting a good first innings total."
After leaning into those verbal strokes, Williamson deflected an oratory single to get off strike.
"It was great to bat alongside Jeet [Raval] who played superbly at the top of the order in all games this series [for 256 runs at 64] which is tough against one of the best new-ball bowling attacks in the world.
"I also spent time batting in [a fifth-wicket 88-run] partnership with Mitch Santner in a tough spell of bowling yesterday morning.
"It shows we do have the belief and what it takes. It'd be nice not to have to 'bounce back' [from the Basin Reserve] but I think we showed consistency with the number of partnerships created and also with a relatively inexperienced bowling attack.
"There was a bad [third] day's cricket in Wellington, but ultimately the series was a positive experience to build on."
