England extended their winning streak to 16 matches when a late Elliot Daly try secured them a 21-16 win over Wales in Cardiff on Saturday.
In an attritional encounter, in which both sides went at each other hammer and tongs for the full 80 minutes, Wales will be kicking themselves for losing this Test as they dominated for large periods.
For the second successive week, England had to dig deep and they showed again that it will take a special effort to dethrone them as Six Nations champions.
Both sides gave their all on attack and defence but England showed greater composure in the former department and eventually outscored their hosts by two tries to one.
They were trailing for most of the match but Daly's effort in the 75th minute, where he showed a superb burst of speed before shrugging off a tackle from Alex Cuthbert to score the matchwinning try, eventually secured them the result.
Although England battled for large periods there were several outstanding individual performances with Joe Launchbury and Maro Itoje deserving special praise for superb efforts in the battle up front.
The opening half was a thrilling affair with plenty of end-to-end action as both side gave the ball plenty of air in a bid to gain the ascendancy. And although England had the better of the opening exchanges, Wales gained the upper hand as the half progressed and led 13-8 at the interval.
The home side took the lead as early as the third minute when Leigh Halfpenny opened the scoring from the kicking tee after Courtney Lawes was penalised for a ruck infringement.
England bided their time and were level by the 11th minute when Owen Farrell added a penalty after Scott Williams was blown up for a high tackle on Jack Nowell.
The visitors started to dominate and were rewarded in the 19th minute when Ben Youngs dived over from close quarters after Maro Itoje, Joe Launchbury and Mike Brown were all stopped just short of the try-line.
That try saw Wales stepping up a few gears on attack and they spent most of the next 20 minutes camped inside England's 22.
Another Halfpenny penalty made it a two-point game and two minutes before the interval, Wales took the lead when, from an attacking scrum inside England's 22, Liam Williams glided through a gaping hole in the visitors' defence — after Scott Williams was used as dummy runner — before diving over next to the posts.
Wales had their tails up and were fastest out of the blocks after the break but could not convert their dominance into points.
England were battling to assert themselves in the forward battle which resulted in their captain Dylan Hartley being replaced by Jamie George after 50 minutes.
Five minutes later, Farrell reduced the deficit to two points when he slotted his second penalty but Halfpenny soon restored his side's five-point lead when he added his third penalty from the kicking tee on the hour-mark.
That would be the last time the hosts would score points, however, as another Farrell penalty in the 70th minute preceded Daly's stunning score which clinched the win for the visitors and kept alive their hopes of repeating last year's Grand Slam triumph.
The scorers:
For Wales:
Try: Williams
Con: Halfpenny
Pens: Halfpenny 3
For England:
Tries: Youngs, Daly
Con: Farrell
Pens: Farrell 3
Wales: 15 Leigh Halfpenny, 14 George North, 13 Jonathan Davies, 12 Scott Williams, 11 Liam Williams, 10 Dan Biggar, 9 Rhys Webb, 8 Ross Moriarty, 7 Justin Tipuric, 6 Sam Warburton, 5 Alun Wyn Jones (c), 4 Jake Ball, 3 Tomas Francis, 2 Ken Owens, 1 Rob Evans
Replacements: 16 Scott Baldwin, 17 Nicky Smith, 18 Samson Lee, 19 Cory Hill, 20 Taulupe Faletau, 21 Gareth Davies, 22 Sam Davies, 23 Jamie Roberts
England: 15 Mike Brown, 14 Jack Nowell, 13 Jonathan Joseph, 12 Owen Farrell, 11 Elliot Daly, 10 George Ford, 9 Ben Youngs, 8 Nathan Hughes, 7 Jack Clifford, 6 Maro Itoje, 5 Courtney Lawes, 4 Joe Launchbury, 3 Dan Cole, 2 Dylan Hartley (c), 1 Joe Marler
Replacements: 16 Jamie George, 17 Matt Mullan, 18 Kyle Sinckler, 19 Tom Wood, 20 James Haskell, 21 Danny Care, 22 Ben Te’o, 23 Jonny May
Referee: Jérôme Garcès (France)
Assistant Referees: Pascal Gauzère (France), Nick Briant (New Zealand)
TMO: Glenn Newman (New Zealand)
Bouncing back from a first round loss to Scotland, the Irish were superb against the Azzurri as they made it six points from two matches.
Despite falling behind to Edoardo Gori's try on 29 minutes, Rob Howley's men hit back through Jonathan Davies, Liam Williams and George North with Leigh Halfpenny contributing 16 points from the tee in an assured display.
Although their campaign started with a win — and they have now stretched their winning run to 15 successive Tests — the defending champions' boss, Eddie Jones, will not be happy with his side's effort as they had to dig deep to win this one.
Greig Laidlaw secured his side the win after a spirited Irish fightback, with two penalties in the last ten minutes of the match.
It has been a sensational year for the English team after going 13 games unbeaten, claiming victories over all the Six Nations sides and three of the Rugby Championship teams. It is England's first year since 1992 that they haven't lost a single game to make it a perfect season.
The result means the All Blacks finish 2016 with just one defeat, while France failed to make amends for their narrow loss to Australia last week despite playing very well against the World Champions.
For Wales this will go down as a satisfactory win and their third victory of the November Test window. It was only their third ever victory over South Africa and their second successive win over the Boks in Cardiff.
The result is a momentous one for the home side as it means they are the first Northern Hemisphere side, since England in 2003, to beat the Southern Hemisphere's traditional powerhouses of New Zealand, Australia and South Africa in the same calendar year.
It is great result for Scotland who finish off their November Series with two wins from three games, and their only loss came at the hands of Australia who could only beat Scotland by one point.
Fiji finally got a win this series after taking heavy losses against the Barbarians and then England.
Takulua was his side's hero as he finished with a 14-point haul, thanks to four penalties and a conversion, although the Azzurri outscored the Pacific islanders by two tries to two.
Canada outscored Samoa by three tries to one, including a double for in-form wing DTH van der Merwe, but the boot of Leuila, on his first start for his country, proved to be the difference.
Both sides crossed for a try apiece but it was the accurate goalkicking of replacement back Romain Lonca, who finished with an 11-point haul courtesy of three penalties and a conversion, which helped the Barbarians secure victory.
A penalty try and crossings from Bernard Foley and Tevita Kuridrani saw them end with the win, with Foley kicking 10 points on Saturday.
It was always going to be a tough ask to beat the All Blacks twice in three weekends and even though they couldn't pull it off, Ireland should still feel pleased with their performance against the world champions.
The result was in the balance right until the end when Greig Laidlaw secured victory for the home side via a penalty with the final act of this Test, after Juan Manuel Leguizamon was penalised for an illegal tackle on Ross Ford.
Canada led early on thanks to a penalty from scrum-half Gordon McRorie but on five minutes Florin Vlaicu responded to level in Bucharest.
It looked like the Brave Blossoms had snatched a draw when Yu Tamura converted Amanaki Lotoahea's 74th minute try, but Wales went down the other end of the field, with Davies showing composure to slot the three points.
The win means that England have now gone 11 games unbeaten and have won every game under Eddie Jones. Fiji who were trying make up for a 40-7 clobbering at the hands of the Barbarians last weekend continue their losing run.
So, this is what rock bottom looks like. Or perhaps the Springboks were already there and didn't realise it. South Africa's downward spiral is now complete. Allister Coetzee must fear for his job.
As the scoreline suggests, this was a tight contest and the home side's forwards deserve plenty of credit for the result as they laid the platform to victory with a dominant display in the tight exchanges.
Chiefs wing James Lowe was a double try scorer for the touring side with back-to-back efforts for Colin Cooper's side, who raced out into a 26-3 lead.