He followed that with two birdies through his next four holes, before undoing much of his good work with a double bogey at the seventh and a bogey at the ninth.

His three-under-par 67 put him eight under on 132 overall and one shot ahead of Matt Jones, who also carded a 67 and was two ahead of Dudley Hart – the 2000 winner of this event.

John Mallinger and Ben Crane were tied for fourth – three shots back – and Ernie Els, the world’s fourth-ranked player, was bunched with five others at three-under 137.

Davis, who is aiming for his first PGA Tour win, said: “Around this course, I think you’d need about a 20-shot lead with one round to go.

“You know around here, it’s going to come down to the last nine holes, just the way the course is set up. I can’t see anybody getting a six-shot lead out there tomorrow.

“I’m sure every player’s got a few hiccups around here.

“But it’s a welcome return to form and it’s where you want to be.”

Australian Jones had birdies on three of his first five holes, before a bogey on the 11th left him two shots under. However, the 27-year-old carded his 10th birdie of the tournament on the next hole to help finish his day in second place.

The 39-year-old Hart carded six straight birdies on the front side to move to six under, but a double-bogey at the par-three 17th kept him from finishing the day with a share of the lead.

“You don’t birdie six in a row very often,” said Hart.

“You know, everybody out here has gone through stretches where they have done that. It’s just hard to describe, really – just things are clicking right. The putts are falling, and good things are happening.”

First-round leader Luke Donald shot a four-over 74, including a quadruple-bogey on the 14th to fall six shots back.

Defending champion Mark Wilson shot a three-over-par 73 for the second consecutive day and missed the cut.