Wales head coach Warren Gatland greeted his team's rise to No 1 in the world rankings after beating England 13-6 in Cardiff by saying, "it's just a number, nice for a day", before warning England that if they were to meet again in the World Cup quarter-final "it will be a hell of a battle".
England head coach Eddie Jones piled the pressure on Wales' new status by saying, "Well, that makes them favourites for the World Cup."
Wales extended their winning record at home to 11 Tests dating back to 2017 with a performance that was full of character after their limp showing at Twickenham six days earlier, inspired by a man-of-the-match display from under-fire fly-half Dan Biggar.
"The boys turned up properly today after lacking edge last week," said Gatland. "If we had lost again to England it could potentially have had an impact if we were to meet them in the World Cup quarter-final. The ranking is a nice accolade but we won't be trumpeting it from the roof-tops.
"There will be lots of Kiwi journalists saying that it is a joke. But we won't be making a fuss about it. The boys wear this jersey with pride, and if a team is going to beat us they are going to have play pretty well because these boys are very proud Welshmen who are not going to roll over easily. We showed some big cojones today."