Louis Oosthuizen has earned the third spot of the year in what is arguably the most difficult tournament to qualify for, the PGA Grand Slam of Golf, which will be held at Port Royal Golf Club in October.

Also invited will be Phil Mickelson, who won The Masters in April, Northern Ireland's Greame McDowell who claimed the US Open last month, and the winner next month's PGA Championships.

Yesterday, the image of Gary Player running the gauntlet of hostile American fans on the way to a first US Masters triumph almost 50 years ago helped to spur Louis Oosthuizen to victory in the British Open.

Player, who in 1961 secured the first of three Augusta green jackets, phoned his fellow countryman yesterday morning ahead of the final round at St Andrews.

"He was saying just to stay calm out there, have a lot of fun and he said the crowd was probably going to be on Paul Casey's side," the South African told a news conference after romping to a seven-shot victory over Briton Lee Westwood.

Oosthuizen's playing partner Casey, also of Britain, finished a stroke further back in a tie for third place.

Few would have tipped 200-1 outsider Oosthuizen before the tournament and even when he had built a sizeable lead the question marks remained, as he had only won once before on the European Tour. However he had a trick up his sleeve, or more precisely, his glove. The 27-year-old said his mind could sometimes wander on the golf course.

"I think of all kinds of things and it's hard for me to then get back into the moment," said Oosthuizen after a closing 71 gave him a 16-under tally of 272.

"I've got a little red dot on my glove. Whenever I look down at it I know exactly what's my trigger. Forget about everything, just focus, hit the shot now. It worked great the whole week.

"Last week (at the Scottish Open) as well. I didn't make the cut there but it worked good. Every shot I hit I was up for it. The last thing I wanted to do was hit a shot and then walk up and think, 'What were you thinking?'." Asked how it felt to be called the British Open champion, a beaming Oosthuizen replied: "It sounds good".

He was also delighted to lift the coveted Claret Jug on the 92nd birthday of former South African president Nelson Mandela.