For all the pre-match talk of Grand Slams, this was almost instead the grandest of shocks.
England's spluttering, stuttering means, unarguably, that a long-awaited Slam is still on when they march into the dragon's den in Cardiff next Saturday afternoon.
Equally indisputably, a significant and sustained improvement will be required against a revived Wales if a first clean-sweep in a decade is not to go down the gurgler as it did so rapidly in Dublin two years ago.
This unflashy England management team are not big on grandstanding public pronouncements, but they do have one key private mantra: you are never quite as good as your acolytes will sometimes say, and never as poor as your critics would have others think.
It is a neat way to balance out the sort of fluctuations in form that every team will experience, particularly one as comparatively inexperienced as this England side.
And this was indeed a wobble, a dip that threatened at times to become a nose-dive.
Coach Stuart Lancaster looked afterwards like a man who had just witnessed the most disjointed display of his 14-month regime. "No-one is punching the air," he admitted. "It's a pretty quiet dressing-room because we know that we should have done better."
From his players, too, there was relief rather than celebration. Three of the last five clashes between these two sides may have been settled by margins of five points or under, but they took place in Rome. The aggregate score in six matches at Twickenham is 274-66, with England averaging six tries per game. Two years ago the men in white ran in almost 60 points in a match as one-sided as a North Korean election.
At the same time, they will awake on Monday morning sitting pretty atop the championship, the only unbeaten side in the competition, with a chance to do what only a World Cup-winning England side has done this century.
"We've had our moments when we've played very well, and the progression is four wins from four," said defence coach Andy Farrell on Sunday night. "It's not a bad place to be in."
Lancaster argued that this is not the same sort of Italy team that used to trot out expecting the butcher's knife. England might have been 250-1 on with some online accountants, but with skipper Sergio Parisse his usual buccaneering self and almost three times as many Test caps in his team as in Lancaster's, there was belief where previous incarnations have faltered.
Those of a particularly generous disposition might even point out that England survived the Azzurri assault as France in their home stadium could not, even if that is a reading that glosses over the very real problems they experienced.
Given the chance to shine by his old mentor Lancaster, scrum-half Danny Care endured one his most disappointing afternoons in an England shirt. Outside him, Toby Flood was faultless from the tee but unable to send his back line scampering as he had in the corresponding fixture two years ago.
Throughout the team there was considerable resolve in defence and absolute parity in possession and territory. There was also a lack of creativity, and a glaring absence of ruthlessness when chances did come.
Two clear overlaps were butchered, once when Flood was held up on the left after Alex Goode's short pass ignored men queuing up in empty acres outside him, and again when Brad Barritt characteristically sought contact rather than the killer pass after Mike Brown's side-stepping break.
There was also no evidence of a return to form for Chris Ashton, and further evidence for the opposite. Half-breaks that two years ago had him haring up on the ball-carrier's shoulder now go untouched; half-chances when he has both ball and space seldom go forth to multiply.
This was only the second time in Six Nations history that England have failed to score a try at Twickenham. They have now scored only one try in their last three matches, and that - Manu Tuilagi's gather and dash against France - was the consequence of deflection rather than inspiration.
Up front the scrum first succeeded, then faltered, then stood firm again, the set-piece flaws that have dogged the whole tournament once again turning the engagement into the least exciting of lotteries.
"Collectively our pack survived a real scare, because we were hanging on there," admitted forwards coach Graham Rowntree afterwards. "We've come through a massive scare."
At least, after a Six Nations that has strained rather than sparkled, we shall have a finale to light up the darkest of wintry nights.
If, until Sunday afternoon, Italy's form had fallen away since that spectacular start against France, so too has the quality and allure of the rugby on offer across the tournament.
A championship that began with Simon Zebo's heel-flick, Luciano Orquera's fleet-footedness and a six-try blitz at Twickenham has become mired in stodgy forward battles and punctuated predominantly by penalties.
If the wintry weather has not helped, neither is it anything new. These have been two months for the hardcore rather than the converts, but the denouement could yet keep the faith alive for another long year.
Wales against England is always a brutal delight. Wales against England when both sides can still win the championship, and one can win the Grand Slam, is the sort of lip-smacker that will ensure we talk of little else all week.
England have completed five of their 12 Grand Slams away from home - three in Paris, one at Murrayfield and one in Dublin. They have never sealed one in Cardiff.
With lock Joe Launchbury leaving Twickenham on Sunday night with his arm in a sling and his second-row partner Geoff Parling substituted with a stinger to the shoulder, England may have to make changes. They also have a strength in depth unrivalled in the tournament.
Wales, so slow to start in the opening match, on so dismal a run of defeats only three games ago, have the chance to finish not just on a high but with their favourite scalp of all.
A home win by eight points will snatch them the championship. Seven points could do it too, since they have a two-try advantage in the title's chosen tie-breaker.
Cold logic would suggest that topping the table, should the Slam be lost, would still represent a fine return for an England side still low on their learning curve.
But cold logic is likely to have little to do with it. Not in Cardiff, at 5pm on a booze-soaked Saturday - not in this fixture, in this season.