Will Greenwood told Sky Sports that every other rugby nation must raise their game to compete with Rugby Championship victors New Zealand and runners-up South Africa.
The All Blacks won the Southern Hemisphere competition for the second year running, beating the Springboks 38-27 in a scintillating clash at Ellis Park which featured nine tries.
New Zealand - who won each of their six clashes in the 2013 Rugby Championship - and South Africa are now headed to Europe for the latest batch of Autumn Internationals.
And Greenwood thinks the likes of Wales and England, the top two in this year's Six Nations, must be at the peak of their powers to have any chance of toppling Steve Hansen and Heyneke Meyer's sides.
"When facing either of these two teams you have to have a frightening level of physicality and endurance," said the former England man. "Plus, your skill sets have to be great and you have to be composed under pressure.
"New Zealand and South Africa have set the bar so high and they produced an incredible game [on Saturday]; these matches are meant to be tight affairs but that was thrown out of the window and we saw an end-to-end encounter.
"But the All Blacks struck when it mattered and their ability to get a seven-pointer when they need it is unrivalled and it's what marks them out as the best side in the world.
"South Africa are second and so the other countries have to readjust."
Ex-New Zealand hooker Sean Fitzpatrick cut a delighted figure after watching his nation overcome the Springboks, and singled out a host of Kiwi players for praise, including No.8 Kieran Read.
Onetime South Africa back Thinus Delport, meanwhile, admitted that his countrymen has been bested by a superior side, but was left nonplussed at some of the choices made by the two-time World Cup winners' playing and coaching staff.
Fitzpatrick said: "I think [coach] Hansen and [captain Richie] McCaw will be delighted with the kids coming through as I thought Brodie Retallick was quite outstanding, Liam Messam led from the front, while Aaron Smith and Aaron Cruden played very well, too.
"The depth of New Zealand rugby continues to grow and Read has turned himself from a journeyman into someone with excellent skill sets and an excellent motor, while he is an outstanding leader as well."
Delport added: "We were beaten by the better side but a couple of tactical decisions should be questioned, like when we tried to run out from deep just before half-time.
"I also did not like the decision to change the front row at 50 minutes when we had the All Blacks on their line, while our defensive organisation [wasn't great at times]."
In the second Rugby Championship duel of the weekend, Australia crushed Argentina 54-17 in Mendoza, with full-back Israel Folau scoring a hat-trick. Read below to see what the Sky Sports experts made of it...
Michael Lynagh: Australia - 1985-95
"This was an Australia I want to see; their kicking games was poor but they got the ball and used it well, and the way Will Genia and Quade Cooper attacked the 9 and 10 channel was very good, while the scrum looked better, too. There appeared to be a spring in their step which has been missing, with Folau playing very well."
Mariano Sambucetti: Argentina - 2001-present
"It was a frustrating defeat for Argentina; there were so many expectations but we failed in defence and while there were many good phases and offloads, there was then that little mistake that ended up benefitting the Wallabies."