England head coach Stuart Lancaster says his team need to improve on their showing against Italy if they are to clinch a Grand Slam next week.
Lancaster's men made it four wins from four in this season's Six Nations with an 18-11 win at Twickenham but, having entered the game as hot favourites, they failed to register a try and were under pressure for much of the second-half.
And, if they are to complete a Grand Slam, they will have to win in Cardiff next Saturday against a Wales side who are on a three-match winning run themselves.
Asked if England's display against Italy was their worst of the tournament so far, Lancaster said: "Yes, I think so, certainly the second half.
"In the first-half we weren't quite accurate enough but we still felt in control of the game. But I felt we let that control slip and Italy pushed us right to the end.
"We have to improve on that performance and it will be a massive step for us.
"We got the win today but it's a quiet changing room and we'll take the lessons out of this. It's set up for a fantastic occasion."
England defence coach Andy Farrell looked ahead to next weekend's meeting in Cardiff.
"We don't talk about favourites. We've not got six days to make sure our preparations are spot on," said Farrell.
"We've had our moments where we have played well and we are four from four, which isn't a bad place to be in.
"Everything is down to that last game and then form goes out the window. It will be another big step for our boys to go down there and handle the emotion and pressure on the day."
England forwards coach Graham Rowntree expressed the coaching staff's relief at clinching the result, specifically with the key lineout steal from Courtney Lawes with time running out. "Massive is an understatement," said Rowntree.
"We've come through a massive scare there and credit must go to the lads for coming through that. The word 'lottery' is used often when it comes to scrums and it swung both ways today."
Will England win the Grand Slam in Cardiff?