The brilliant, calm South African, on 12 under, hasn't shaken off the threat of US major winners Collin Morikawa, who's a shot behind, and Jordan Spieth, who dropped shots on the last two holes to fall back to nine under.

And though he's never quite shaken off the tag of somehow being a nearly-man after six times finishing runner-up in a major since his 2010 Open triumph at St Andrews, Oosthuizen reckons he's ready to complete a wire-to-wire triumph.

RIGHT: Louis Oosthuizen salutes the crowd after carding a one udner 69 and taking a one stroke lead into the final round. PHOTO: Getty Images.

Asked if he could take anything from those second-place finishes, he smiled at Royal St George's after the third round: "Go one better!

"You know, finishing second isn't great, so I will play my heart out tomorrow and see if I can lift the Claret Jug again."

The 38-year-old's still the man to beat after a one under par 69 gave him a three-round total of 198.

Saturday, of course, is "moving day" yet 'Oosty' was quite immoveable, leading at the end of the day yet again following his brilliant 64 and 65 in the opening two rounds.

Behind the major-winning trio are Canada's Corey Conners and American Scottie Scheffler, who lie a shot behind Spieth on eight under.

US Open champ Jon Rahm is in a trio tied for sixth on seven under alongside another Canadian Mackenzie Hughes and South African Dylan Frittelli.

Jordan Spieth bogeyed the 18th hole to lose a share of the 54-hole lead. PHOTO: Getty Images.

Australia's only hope now, Cameron Smith, who was outscored by the 66-shooting Conners, recorded a 68 and is joint-ninth alongside South African Justin Harding and German Marcel Siem.

But the Queenslander rates his chances as "very slim" and reckons he'll have to shoot a 62 to become the first Aussie since Greg Norman back at these same Kent links in 1993 to bring home the Claret Jug.


Adam Scott, the other Australian to make the cut, had two double-bogeys in his disappointing round of 73 which leaves him out of contention at two over.

On another cloudless day, with the wind not too unkind but the fairways firming up and tougher pin placements providing a bit more defence for the venerable links, the one disappointment for 2010 champion Oosthuizen was that he might have gone into the final round in greater command.

What he described as "a couple of loose swings" on his inward nine led to bogeys - which almost felt like a sensation, so excellently has he been playing.

A birdie on the par three 16th edged him into the lead over a resurgent Morikawa, who showed his mettle after slipping back to seven under after six holes.

"It was so great with all the fans there; it felt like it was a Sunday afternoon really when I made that putt and I was taking the lead," said Oosthuizen.

It kept the South African on pole to record a wire-to-wire victory – only the eighth in Open history, with Rory McIlroy's 2014 victory at Royal Liverpool the most recent.

Spieth had been four under for the day after 11 holes and shared the lead with Oosthuizen and Morikawa with three holes remaining, but the 2017 champ bogeyed the 17th and missed a short par putt on the last.

Two back nine birdies put Collin Morikawa back in The Open Championship frame. PHOTO: Getty Images.

Not that Oosthuizen seems at all fazed by the task.

"I'm going to try and stay awake as long as I can tonight because I know the tee time is probably going to be around 3:00, 3:30 again tomorrow," he said.

Does he ever get worked up about anything?

"I was worked up about 45 minutes ago when I hit that (wayward) 5-iron on 15," he smiled.

"But I got myself quickly together and made a great up-and-down.

"So, no, I mean, just chill..."

His grin felt like a chilling warning to his pursuers.