The English media were left lauding Gatland's ability to get under the skin of Lancaster and his players as being a factor in Wales' stirring late rally.
England's 2003 Cup-winning coach Sir Clive Woodward said Gatland had risen to greatness with the win.
"This will go down in the annals and is another feather in the cap for Warren Gatland who will be remembered as one of the great modern-day coaches," Woodward wrote in a column for London Daily Mail. "He rises to the big occasion and takes his team with him. You can only applaud."
Read more: Six things we learned from Wales' win
Graham Henry: England made poor decisions
Lancaster admitted after the match that he was "absolutely devastated", confessing that it had been a "big call" for captain Chris Robshaw to spurn a kick for goal that might have drawn the match at its end.
"It was a big call," said Lancaster, "And if you take it, you have got to nail it." But England's line out was pushed into touch and Wales won a famous victory.
Robshaw admitted responsibility. "The call came down to myself," he said. "I spoke to the kickers and we decided it was a tough kick and that we wanted to go for the win. A couple of lineouts before we had gained ascendancy but unfortunately it did not come off."
Gatland couldn't reveal a little dig after the game.
"I thought England would have gone for goal and got the draw," he said. "Get it right and you are a hero. Get it wrong and you are zero.'
Owen Farrell scored 20 points for England with his boot and Jonny May scored a first-half try, but they simply conceded too many penalties as Wales' superior fitness told in the second half, after they had controlled the first half and were 22-12 up at one stage in the second.
"We were playing so well and yet ended up losing," said Lancaster. "We just gave away too many penalties. I'm so frustrated to have allowed Wales back into the game in the way we did, we've talked a lot about discipline and breakdown penalties, and we gave some dumb ones away which kept them in the game."