England coach Eddie Jones has fired a warning to other nations, saying his side's bonus-point victory over Ireland in Dublin is the beginning of something special.
Desperate to right the wrongs of last year's dismal campaign, which saw England finish fifth in the Six Nations, Jones' side roared to a 32-20 victory away to defending champions Ireland on Sunday (NZ time).
England scored four tries en route to their first Six Nations win against Ireland in Dublin since 2013, ending the Irish's 12-match winning run at home.
"We will be better in the next game, because we are still growing," said the England coach. "We are nowhere near our best.
"This match has nothing to do with the World Cup - it was a stand-alone between a good Ireland side and an improving England team."
Jones still believed Ireland were the best team in the world, despite the All Blacks sitting atop the rankings.
"Well, I don't think that changes in one game. Ireland have been consistently good.
"You guys are writing it, so it must be true. My mother reads the paper and she believes everything you write."
Ireland coach Joe Schmidt said the loss served as a "reality check" less than two months after being name Team of the Year at the World Rugby awards.
"That is a reality check about the physicality that will be required to be successful in this World Cup year," said Schmidt.
"England collectively delivered a simmering physical intensity. It was a suffocating place to be out there - it's a challenge to all our confidence.
"It was very difficult to contain their forward momentum. It's something that happened two years ago against the All Blacks.
"We got bullied here two years ago and it happened again. You've got to be prepared to give as good as you get and we didn't do that tonight.
"We probably didn't have the same physical edge that they did. We've got to make sure our solutions are that we get better pressure on the ball.
"We didn't get a turnover on the ground tonight.
"There was quite a lot of volume with them stirring each other up and getting off the line, and they backed that up with a lot of physical intent.
"I think we were physically bettered. I don't think I've seen a game where our opponents got so many physical, dominant tackles, where our opponents have carried physically in the manner that they did."
England will look to back up their performance, when they host France next Monday, while Ireland travel to Murrayfield to face Scotland, who are atop the standings, in their next match on Sunday.