American Steve Stricker equalled the lowest round in major history with a stunning 63 to take the lead on day one of the 93rd US PGA in Atlanta.
The 44-year-old world number five carded seven birdies in a bogey-free round in sweltering heat to lead by two from countryman Jerry Kelly.
Another American Scott Verplank was four back on three under with half the field still to complete round one.
"I didn't know what to expect and maybe that was a good thing," said Stricker.
Chasing his maiden major title, Stricker missed a 10ft birdie putt on the last.
"I realized it was for 62 but didn't realize it was for history," he said.
"It never really registered. I was just trying to make a birdie and never thought about the history of it. I hit a good putt. It just didn't go in."
Stricker began at the 10th and opened with three birdies in a row before adding others at the 260-yard par-three 15th and par-four 18th.
He picked up further shots at the first and the fifth to claim the first 63 in a US PGA since Tiger Woods in 2007 in the second round of his victory at Southern Hills.
