The Major monster goes into round two of the Masters sharing the lead alongside fellow American Bryson DeChambeau after putting the controversy surrounding the two stones he recently shed in double-quick time to one side.
Koepka, who has agreed to pose tastefully naked for ESPN’s Body Issue magazine, has abandoned his 1,800 calorie a day diet after admitting he went at his drive to look buff over-zealously.
But after a poor run on the PGA Tour he has bounced back at Augusta as he hunts down what would be an incredible fourth win in the last eight Majors.
“I’m eating a little better this week. My chef’s cooking up some good food. I want to make me happy, not anyone else and I knew I was going to be ready for this week. I’m not going to jeopardise any Major Championship,” said Koepka.
“I enjoy the big stage, I enjoy Major Championships, that’s what you are remembered for and that was probably the best ball-striking round I’ve had in a Major Championship.
“Whatever Major Championship it is, when I arrive there, I get a good feeling. I’m just dialled in.”
DeChambeau matched Koepka with a six-under-par 66 in the first round which saw him rattle off four birdies in a row over the last four holes.
He hit the flagstick from the fairway at the 18th after almost making the first hole-in-one of his career at the short 16th.
DeChambeau spent 14 hours working on his wedge play last Wednesday in Dallas in a marathon session which paid rich dividends.
“I don’t make my bed at all but inside the game of golf, I can sometimes become very OCD,” he said.
“It’s a positive thing that’s allowed me to play well. What a magical back nine.”
Phil Mickelson, 48, bidding to become the oldest champion in Major history, is one shot further back with Ian Poulter two behind leading the European challenge.
“My whole game was together, from the first hole to the 18th hole. I’m very happy with today’s work,” said Poulter.
But favourite Rory McIlroy is seven shots back after a disappointing opening 73, and needs a low round today to give him a chance heading into the weekend.