Justin Rose "reset" after a tough start at the Masters before firing a stunning seven-under 65 to take the first-round lead on Thursday.
The Englishman produced his best ever round at Augusta, equalling the second largest first-round lead in Masters history with his four-stoke advantage.
Such a position looked unlikely for Rose when he bogeyed the seventh hole to be at two over.
But his response was incredible with an eagle at eight and birdie at nine, before six more birdies followed on the back nine.
Rose said the eagle at the eighth hole was what he needed to settle into the tournament.
"It maybe settled me down if I'm honest. I kind of knew two over through seven is not the end of the world, but also knew you're going in the wrong direction," he told a news conference.
"You can't win the golf tournament today. Even with a 65 you can't win it today. You can only probably lose it today, obviously.
"And I was very aware being a couple over through seven that things weren't – I didn't hit the panic button yet, but I reset just prior to that and thought if I can get myself back around even par, you know, that would be a good day's work.
"So obviously the eagle, boom, straight back in there, and I guess almost just piggybacking with a birdie straightaway at number nine, suddenly I turned in one under, and I could feel like I could actually leave the front nine behind as a job well done and kind of move to the back nine and try and build a score.
"From that point on I kind of was aware that the lead was only three, and if I played a decent back nine it was basically a very good day's work. And then I just got on a great run and was just trying to stay out of my own way and just try to get it to the clubhouse and keep doing what I was doing."
Rose, the 2013 U.S. Open champion, said his putting was key to his incredible round.
"I putted the ball beautifully and read the greens unbelievably well. If you had said to me walking up the eighth hole, I'd have said no chance, this course is playing a little too tricky for that," he said.
"But it's incredible. It's a good reminder that you just never know what can happen out there, just to stick with it on the golf course."
Rose is four strokes clear of Brian Harman and Hideki Matsuyama.