Having spotted a weakness in the English ranks, his tactic almost proved inspired as the underdogs led at half-time before Jonny Wilkinson's boot steered England to a flattering 28-17 win.
The victory earned Clive Woodward's men a semi-final encounter with France in Sydney next Sunday, although on the evidence of this performance it is a tie England will struggle to win.
"I have always had a question mark about the way England defend," he said.
"I felt if we got behind their umbrella defence we could move the ball wide and create a big threat to their forwards and run them around the park.
"The way they play they do not have to do too much running, they stay where they are and the ball is brought back to them.
"We wanted to ask question marks over their fitness and their ability to get around."
The magnificent Welsh performance came just seven days after they had stunned the All Blacks with an equally superb display.
Wales won the try count 3-1 but Hansen admitted their penalty count in the second half had cost them dearly as Wilkinson continued to slam over the penalties.
"Rugby is not just about scoring tries," he said. "It is also about not giving away penalties and we gave away too many in the first 20 minutes of the second half.
"At no stage did I feel we couldn't win the game and if England are honest with themselves they will know that as well."