The American missed a 3ft 3 inch birdie putt on the 3rd hole.
WATCH: Brooks Koepka Misses Crucial Short Putt At PGA Championship
It has been an electric start to the final day of the 103rd PGA Championship with the leaders making errors and a packed chasing pack dropping plenty of birdies in front of them.
One of the moments of the round so far - unless you're a Koepka fan - was this whiffed 3ft putt for birdie on the 3rd hole.
It was a guilt-edged chance to tie Mickelson at 6-under par and most - including the Sky commentary team in the UK - had virtually given him the birdie.
After making a double-bogey 7 on the par 5 2nd hole, the missed putt continued a shaky, error-ridden start to Koepka's round.
After his Saturday 70, Koepka was clearly very frustrated with his putting and wanted to get his pace and accuracy with the flatstick right before the start of the final round.
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“That was the worst putting performance I think I’ve ever had in my career. Can’t get much worse. I thought 70 was about the highest I could have shot today.
“I don’t know why I felt like I made a big enough stroke, it was just maybe felt a little slow."
“This putting green I think is a little faster than the greens today. I don’t know, I’ll go figure this out here shortly."
“From inside 10 feet, I’m usually banging it in the back of the cup. If it misses it’s going three, four feet by. I didn’t have any of those, so obviously it’s a speed issue and not trusting it."
At the pace his putt on the 3rd lipped out, it is clear he was trying to revert to his 'banging it in the back of the cup' technique.
However with the wind gusting over 20mph and the greens looking increasingly fast and shiny, putting is looking tough out there for the entire field.
WATCH: Brooks Koepka Misses Crucial Short Putt At PGA Championship
