Louis Oosthuizen deserves his place at the top of the Open Championship’s leaderboard. He has played superb golf, littered with touches of intelligence where he has made the most of the favourable conditions he has played in. The South African is a proven winner as well; a victory in the 2010 Open de Andalucia complementing much success on his native Sunshine Tour.

Though a flock of players made something of a move yesterday, Oosthuizen’s biggest challenge will surely come from the man he is playing with. Paul Casey was in fine fettle during Saturday’s third round. Shaking off any crowd disruptions that have plagued his mood in the past, he was able to manufacture one of the rounds of the week, playing the Old Course’s front nine in just 31 strokes. That he didn’t capitalise on the home stretch with no birdies for an even 36, he was still able to smile, knowing he is well placed to make something of a charge today.

Casey will certainly bring pressure to Oosthuizen. While the South African plotted along merrily with much crowd control in his pairing with Mark Calcavecchia, he will not be afforded anything of the sort today. The galleries are eager for homegrown success – well, British anyway – and with every added body comes added pressure. Casey is better prepared to handle this.

Though conditions are relatively friendly – the wind is gentle but always has the potential to bite – the pin positions will ask plenty of questions with only a handful deemed to be easy. Casey should play the aggressor, while any plans Oosthuizen has for protecting a lead and playing for the heart of the green could only add to the nerves.

Whatever happens the Englishman needs to make his move early. If he can apply the same game plan to the front nine that he demolished yesterday, you can expect those galleries to get even bigger, and the 11-year wait for a British winner at the Open could well be coming to an end.