A flawless four-under-par 67 took Poulter to 13 under in South Carolina, one ahead of Korea's Si Woo Kim and American Luke List as the Ryder Cup star aims to become the first English winner of the event since Sir Nick Faldo in 1984.

Poulter's recent upturn in form has come about after reverting to the putter with which he helped Europe pull off the 'Miracle of Medinah' at the 2012 Ryder Cup.

After struggling on the greens en route to a missed cut at the Valspar Championship, Poulter revealed he had given away his putter before making the switch.

"After missing the cut in Tampa, I was in disarray, so I gave it (putter) to a kid at the back of the green," he said in an interview broadcast on Sky Sports Golf.

"I was thinking 'what shall I use'? - I've got an office full of old putters and I was looking at it thinking 'surely I can remember how good this thing was and how good I was'.

"I stood over it, I opened my shoulders Friday morning in Houston and I saw the line of the putts a lot easier than I was. Holed a 20 footer, holed a 30 footer, and it's like 'OK, we're ready to go now'."

After a tap-in birdie at the long fifth, Poulter converted from 14 feet at the sixth and made further back-to-back gains from close range at the 12th and 13th.

Asked about his prospects on Sunday, Poulter added: "Tomorrow's about patience; it's going to be drizzly, it's going to be difficult.

"Trust myself, trust my instincts, trust my ability. I know how to get it done but I've got to relearn it - it's about hitting the shots under pressure and delivering when you have to deliver. Hole the putts at the right time."

List also carded a four-under 67, while Players Championship winner Kim signed for a 68.

Chinese Taipei's Cheng-tsung Pan and American Billy Horschel share fourth on 11 under.