Eddie Jones said England had undergone a "rebirth" after his side edged out world champions South Africa 27-26 at Twickenham on Saturday.
England outscored the Springboks three tries to one, with Manu Tuilagi, Freddie Steward and Raffi Quirke all crossing in impressive fashion, although it needed a last-ditch penalty from ice-cool fly-half Marcus Smith to seal victory in their first match against South Africa since the Springboks' 2019 World Cup final triumph in Japan.
Makazole Mapimpi, a try-scorer in that showpiece fixture, crossed again for the Springboks' lone try on Saturday.
But England indiscipline allowed South Africa fly-half Handre Pollard to kick five penalties, although he missed two attempts, with Elton Jantjies and Francois Steyn adding further goals.
England's win was all the more remarkable given an injury-hit side conceded 18 penalties to South Africa's eight in what was both teams' last match of the year.
Victory meant England had completed an autumn series clean sweep following wins over Tonga and Australia.
Their recent form has been a far cry from England's lowly fifth-place finish in this year's Six Nations, with the emergence of Smith, Steward and Quirke all encouraging signs ahead of the 2023 World Cup in France.
"We said in the summer that the (British and Irish) Lions tour (of South Africa) draws a line in the sand, and that you need to regenerate and have a little bit of a rebirth to go to the World Cup," Jones told reporters.
"There's some good players coming through but we've got some pretty good experienced players too," he added.
"Our stated aim is to win the World Cup, so we want to be better in the next campaign."
- 'Work in progress' -
The 22-year-old Smith, in just his fifth Test, maintained admirable composure against the Springboks' aggressive defence, especially as he did not have injured England captain Owen Farrell alongside him at inside centre.
"Well, he's a work in progress, and each game he's going to get a little bit better," said Jones of Smith. "I thought he did a great job today, but he's going to be better in the Six Nations."
But Jones insisted this victory was no payback for England's 32-12 defeat in the World Cup final.
"No, I think as I said before the game, it's a one-off game between the first and the third in the world," said Jones. "We're happy to knock off the top team in the world."
For South Africa, this was a third narrow loss this year but coach Jacques Nienaber was upbeat despite a defeat that denied the Springboks an unbeaten tour after their wins over Wales and Scotland.
"It's obviously disappointing, it's the third Test this year that we've lost that way, having led late on," said Nienaber, whose side had to play the last five minutes without Siya Kolisi after their inspirational captain was shown a yellow card for taking out Joe Marchant in the air.
South Africa enjoyed a 2-1 series win over the Lions in a year where they also suffered several reverses, with Nienaber saying: "This is a team that's better than its win percentage. It's a team that's better than that.
"But in saying that I think we lost a lot of development in 2020 because we didn't play any Test matches. So this year has been for us, and I've made no fuss in saying that I don't think we're there yet.
"But now we know what we've got to build on and there's a lot we can work on."