Oosthuizen in shock after Open triumph

Open champion Louis Oosthuizen today admitted it could take a week for his amazing victory at St Andrews to sink in.

Oosthuizen was a 200/1 outsider at the start of the 139th Open Championship, but ended up leaving the world's best golfers trailing in his wake with a stunning display.

The 27-year-old South African carded rounds of 65, 67, 69 and 71 for a 16-under-par total and stunning seven-shot winning margin over world number three Lee Westwood, with Paul Casey, Rory McIlroy and Henrik Stenson a shot further back.

After 12 holes of the final round Oosthuizen was 17 under par and in sight of the record low score in major history - 19 under par set by Tiger Woods here in 2000 - but with the Claret Jug effectively secured, he could simply concentrate on enjoying becoming the fourth South African Open champion after Bobby Locke, Gary Player and Ernie Els.

'It was unbelievable,' admitted Oosthuizen. 'After the 12th it became a bit difficult, having such a big lead, to stay calm and focused, but I'm glad I had an eight-shot lead on the 17th tee!

'I kept cool and calm the whole way but it's probably going to hit me tomorrow or next week what I've done.'

Oosthuizen held a four-shot lead over Casey going into the final day, but his lead was down to three after a bogey on the eighth.

However, he then drove the green on the 352-yard ninth and holed from 40ft for an eagle - Casey made birdie to be four behind - before Casey suffered a triple bogey seven on the 12th to Oosthuizen's birdie three.

'It was actually very tight until the 12th hole,' insisted Oosthuizen, who had only previously made one cut in a major, shooting closing rounds of 81 and 77 to finish last in the 2008 USPGA Championship.

'It could easily be I make bogey and Paul makes birdie, and it's a one-shot game. The minute he made that seven, that birdie putt to me meant a lot for momentum on the next six holes.

'My caddie played a big role then because obviously your mind is going, thinking what you're going to say in your speech, things like that. But whenever I got to the ball I was fine.

'I just focused on the shot that I had and even on my little putts with that big lead, I wanted to take all my time, not do anything silly and not put myself under any pressure.'

Oosthuizen's win came on former South Africa President Nelson Mandela's 92nd birthday, and Oosthuizen added: 'That's amazing.

'I woke up on Sunday morning and didn't know it was his birthday, but I saw it on the news on the internet. It felt a bit special out there.

'When I walked down 18 I was thinking about his birthday. What he's done for our country is unbelievable, so happy birthday to him once again.'