A disjointed and error-strewn England needed a brilliant goalkicking display by Toby Flood to beat Italy 18-11 at Twickenham and set up a Six Nations championship decider against Wales in Cardiff next Saturday.
England will have to play a lot better than on Sunday to secure a win that would give them their first grand slam since 2003 and their second title in three years while Wales, who beat Scotland 28-18 on Saturday for their third tournament win, would retain their title if they won by eight points.
Flyhalf Flood, playing instead of the injured Owen Farrell, scored England's points as he landed all six of his penalty attempts but Italy played most of the rugby and completely dominated the second half, scoring the only try through winger Luke McLean.
England led 12-3 at halftime but, instead of pouring on the points to make Wales' task tougher, they were forced to defend for long periods, often desperately, against a team who had lost by an average of almost 35 points on every previous Twickenham Six Nations visit.
"We will have to be a lot better than that," England coach Stuart Lancaster told the BBC looking ahead to next week's showdown. "It will be a big step up.
"I'm disappointed we weren't quite accurate enough. We let the control slip in the second half and Italy pushed us right to the end."
England actually started full of running as, despite a freezing arctic wind blowing through Twickenham, it was dry and firm underfoot.
However, they struggled to turn that early dominance into points and lost their way, even when Italy were reduced to 14 men after Italian scrumhalf Edoardo Gori was sin-binned.
Four Flood penalties to one by Luciano Orquera had the hosts 12-3 ahead at the break with the crowd ruing three excellent try-scoring opportunities wasted by poor execution or decision-making.
CHIPPED WIDE
A try eventually arrived 10 minutes after the restart but it was Italy who claimed it, and deservedly so, as they were well on top. A horribly-sliced clearance kick by Danny Care went straight to an unchallenged Alessandro Zanni and Orquera then chipped wide for McLean to score in the corner.
Orquera missed the conversion and a penalty soon after but Italy kept their spirits up and, instead of fading in the final quarter as they have so often before, they stepped up their game and took charge.
Showing some crisp passing and real aggression at the breakdown, the Italians poured forward and forced England to defend their own line for long spells while barely venturing over the halfway line themselves.
That defence held firm, however, to prevent what could have been a match-drawing try and leave the fifth-placed Italians frustrated at being unable to add to the two points gained from their first-day victory over France.
"It was important to get the win," said England captain Chris Robshaw. "We were under no illusions, especially after last year in Rome (when England won 19-15).
"There were moments we played very well but a little bit of execution let us down."
A seven-point win for Wales on Saturday would leave the teams level on points and points difference and see the championship decided on tries scored.
Wales have scored seven to England's five in the first four rounds. If the two end level on tries too, the title would be shared.
Italy have now lost three in a row and host Ireland in their final game.
Their fullback Andrea Masi was named man of the match and was frustrated not to have taken something from the game.
"It was a very good performance," he said. "We came from two poor games and we played better rugby with much more physicality."
