However, the former US Open champion then bogeyed the 17th in a round of 71 to finish 11 under par, one ahead of Japan’s Hiroshi Iwata and two ahead of Ryder Cup team-mate Martin Kaymer and Masters champion Bubba Watson.

Kaymer’s 66 was the lowest round of a cold, damp day, while Iwata birdied two of the last three holes for a 68 in his first appearance in a WGC event.

Watson had been McDowell’s closest challenger when he birdied the second and third and then almost holed his approach to the 603-yard eighth hole for an albatross, but missed the eagle putt from five feet and had to settle for a birdie.

The left-hander then made a costly mistake on the 10th when his simple approach to the green plugged in a bunker, from where he could only blast out to 40 feet and three-putt for a double bogey.

But after dropping another shot on the 12th, Watson birdied four of the last five holes, marred only by a three-putt bogey on the 17th.

“I played reasonably solid today,” said McDowell, who has yet to win a WGC title. “I thought conditions were a little bit more difficult, colder, obviously a little bit of overnight rain made the golf course play a little bit longer.

“I didn’t quite score as well as I did the last couple days but really gave myself some confidence from a ball-striking point of view that I can get the job done tomorrow.

“And let’s be honest. Yes, I had a three-shot lead overnight and it’s only one now, but I’ll take this position any week that you offer it to me, a one-shot lead going into the last round on a golf course that I enjoy.

“I am excited about the challenge tomorrow and really looking forward to it.

“It would be huge to win but I can accept whatever happens. I feel like I am turning the corner from a lot of points of view, mentally, physically and in my personal life a lot of good things are going on.

“I am excited about another opportunity to win a golf tournament. If it happens I will be very happy, if not things are moving in the right direction.”

McDowell admitted had never heard of nearest challenger Iwata before this week, but the world number 127 revealed he is quite well known in his native Japan.

“I’m kind of relatively short tempered, so I always focus not to get too angry at myself,” Iwata said. “I believe I’m doing pretty good at that at the moment, so I just want to keep that going.”

Asked if he usually got angry quickly, Iwata added: “I’m pretty famous for that in Japan.”

US Open champion Kaymer could be McDowell’s biggest threat given his record at the venue, the German shot a closing 63 on his way to victory three years ago and also holds the course record of 62.

“Finally I could make some putts today, that was nice,” the 29-year-old said. “The first two days I played really well but the putter was a little cold.

“Today I make a couple mid-distance putts, only one bogey so I think I put myself in a good position.

“Obviously you need a little help from Graeme in order to win, but I’m playing really well and that’s all I can do.”

World number 10 Rickie Fowler and South African Tim Clark are three off the lead on eight under par, with last year’s runner-up Ian Poulter and Denmark’s Thorbjorn Olesen another shot back. Poulter had been in second place at halfway but could only manage a third round of 72.