There are just 18 holes between Louis Oosthuizen and the possibility of winning his second Open Championship when he tees off for the final round at Royal St George’s in Sandwich, Kent on Sunday afternoon.

And while there were moments in the third round when the chances of his hoisting the Claret Jug in triumph for the second time after he won at St Andrews in 2010 seemed to be slipping away, his belief that he can lead this year from wire to wire will be unwavering in the final round.

“It’s human to think of lifting the trophy, and it is on your mind,” he said. “But I think you just need to know it and how to handle it. Once we are on the golf course, it’s all golf. So, in a way, you need to believe you can lift that trophy as well. If you think about it beforehand, think that you might win this championship, I think that’s great. You have to believe you can do it.”

With two runner-up finishes in major championships this year already, to go with the four he already had, he has not only had to handle the incessant questioning from members of the media about how he plans to try and change things up. He also, of course, has to deal with whatever demons those second places might have nurtured in his own head.

The shaky level-par 70 he carded in his third round was probably an indication of those very doubts in his mind. Each time he hit a shot that was even vaguely false, he could be seen rehearsing a practice routine in an attempt to rectify whatever tricks his mind might have been playing with a swing most of the world’s top players would kill for.

In the final round, however, there won’t be space for even the slightest doubts. And Oosthuizen knows that. “It’s not like you can hang in with the lead and just hit a few shots going in,” he said. “You need to still play proper golf and place the ball really well to avoid bogeys. I’m not going to do something silly, taking any possible shot on. But if there is an opportunity to be more aggressive, you’ve got to do it if you want to win a championship.”

Oosthuizen has looked utterly convinced of his own ability to win throughout the week. That’s not to say he expects to win, because he, of all players, knows the curveballs that links golf can throw at him.

But the sense of purpose he shows is visible, almost tangible.