England head coach Eddie Jones has challenged his side to claim a first Six Nations Grand Slam in 13 years.
Saturday's 25-21 win over Wales at Twickenham means England can secure a clean sweep if they beat France in Paris next weekend.
"All we've got to do now is worry about preparing well. If we prepare well, we'll play well," Australian Jones told BBC Sport.
"It's definitely on and the aim for us now is to win the Grand Slam."
England can only be caught at the top of the Six Nations table if France overcome Scotland on Sunday and then Jones' side a week later, while overturning a massive points difference.
Wales almost pulled off a remarkable comeback against England, though, fighting back from 16-0 down at half-time to within four points.
It was reminiscent of the sides' World Cup meeting last year, when Wales overturned a 10-point deficit to effectively knock England out at the group stage, but this time the hosts hung on.
"Wales have been together for eight years now. We've literally been together for six weeks," said Jones, who was appointed head coach in November but did not arrange his first squad until January.
"So to put in a performance like that shows where the team is going. We're not the finished product but that's the development of the team."
From 'immaculate' to 'strangely disappointing'
England looked comfortable for 50 minutes at Twickenham - Anthony Watson's try and Owen Farrell's four penalties giving the hosts a 19-0 lead.
But Wales hit back through Dan Biggar and, with England prop Dan Cole in the sin-bin, scored two more tries from George North and Taulupe Faletau.
But the hosts were helped home by the precise boot of Farrell, who kicked 20 points.
"We had an almost immaculate 60 minutes and, strangely, in our last 20 we dropped off in intensity," said Jones.
"We made a couple of fundamental mistakes. We were strangely disappointing but at the end I thought we responded well, given we were a man short."
Itoje gets Jones' engine running
Maro Itoje may only be three caps into his international career, but Jones has already seen a marked improvement in the 21-year-old Saracens lock, who was named man of the match.
Jones said: "He's worked really hard. I've been really impressed by his desire and attitude to get better and it was a great performance."
When informed he had been upgraded by Jones, Itoje replied: "Thank God. I'm happy he thinks that."
What the experts said
England's 2003 World Cup-winning scrum-half Matt Dawson on BBC Radio 5 live: "The closer the clock went to 80 the more pressure England were under.
"The two benches were going to be important and Wales had the better bench. Thankfully, the clock won for England."
Former Wales fly-half Jonathan Davies on BBC Radio 5 live: "Maro Itoje was immense for England, a brilliant performance.
"England choked a bit towards the end and cramped up. I think they go to Paris a firm favourite and I can see them winning the Grand Slam."