A 19-12 win was only secured late on through a Scott Williams try and Warburton believed their third victory on the bounce had more than a slice of luck behind it.
"I was on the floor and I looked up and saw him going through and I was just praying it would be a lucky bounce," Warburton told Wales Online.
"When he went over I put my head in my hands because I just couldn't believe it.
"It just feels too lucky. It was the same out in Ireland when Leigh (Halfpenny) got the last minute penalty. I was on the bench then and thinking this can't be true.
"And the luck went our way again with Strettle's try being disallowed.
"I was just praying it wasn't going to be given, although I thought it would be.
"So things are going our way and I think you need a bit of luck if you want to do well in campaigns."
Wales looked up against it in the second-half when fly-half Rhys Priestland was sin-binned however the Principality kept the score to 3-3 in that time.
And to skipper Warburton that ten minute backs-to-the-wall period was a big positive.
"I guess the positives we can take out of it is we went to a really tough place, played 10 minutes of the game with 14 men and still got a result," he said.
"I think we can take a huge amount out of that. It wasn't glamorous, but we got the win.
"We knew Wales hadn't clinched the Triple Crown at Twickenham before.
"That was part of the talk before the game, making history.
"Everyone was so pleased afterwards, passing the trophy round the changing room and having photos and stuff.
"We have got some reward now for all the hard work we've put in over the last six months or so."