I wish I'd emulated Woods's feat of staying out of sand says Oosthuizen

The previously little-known 27-year-old did it at the venue every player most wants to, the 'Home of Golf' at St Andrews, and he did it by lapping the field after Paul Casey's big chance turned into a big disappointment.

Known as 'Shrek' because of a gap in his front teeth, Oosthuizen had no need to get too animated as he turned his four-shot overnight lead into an almost unbelievable seven-stroke triumph over nearly-man Lee Westwood.

England's Casey, triple-bogeying the 12th on his way to coming home in 40 for a 75, slipped to joint third with 21-year-old Northern Irishman Rory McIlroy and Swede Henrik Stenson.

Since 1913 there has been only one bigger victory in the event – Tiger Woods by eight over the same Old Course 10 years ago. This time Woods was only 23rd as victory went to a 200-1 outsider who had missed the halfway cut in seven of his previous eight majors and finished last of the weekend qualifiers in the other.

With a closing 71 and a 16-under-par total of 272, three more than Woods in 2000, he followed in the footsteps of Bobby Locke, Gary Player – four- and three-time winners respectively – and 2002 champion Ernie Els, whose Foundation gave him his career lift-off as a teenager.

His first major title earned him 850,000 and moves him up to 15th in the world rankings.

"It's unbelievable – just amazing," said Oosthuizen.

"It's probably going to hit me tomorrow or the week after. I felt like I played well all week and the biggest goal for me was to stay cool.

"I'd like to have kept the record of not going in any bunker (like Woods in 2000), but I went in one on the 14th.

"It became a bit difficult having a big lead, but I'm glad I had all those shots in hand on the 17th."

Westwood, who lost by one after a closing bogey at Turnberry last year and was runner-up to Phil Mickelson at the Masters in April, is not going to beat himself up too much over this one.

"I know what I've got to do – improve," he said after his final-round 70. "I'm showing a lot of consistency, but it's not quite good enough.

"I'm not sure what it is quite. I keep putting myself in position and in contention – that's all I can do.

"I didn't get off to a quick enough start (yesterday). I thought if I could turn in five under anything was possible, but it was difficult out there.

"The pin positions were tough. This is not an easy course when there's a 20mph wind blowing.

"And Louis is obviously playing really well."

Casey will spend far more time than his Ryder Cup teammate thinking what might have been – and so will McIlroy after starting with a major championship record-equalling 63 and following it with an 80 in Friday's 40mph gusts.

The youngster commendably came back with rounds of 69 and 68 over the weekend, but the damage had been done.

Just before they teed off yesterday Casey had not looked wholly convincing on the practice putting green and after a superb approach to five feet on the first he missed the chance to cut the gap instantly to three.

It was not his putter to blame for his bogey on the second, though. He came up short of the green and, after chipping 20 feet past, bogeyed to fall five back.

Meanwhile, Oosthuizen, 44 places below the Englishman at 54th in the world, showed no sign of frailty as he calmly parred the first five holes.

However, although he added another at the next, Casey birdied from four feet and when the leader failed to get up and down from just off the green at the short eighth the difference was down to three.

Both drove the green on the 352-yard ninth, but when Oosthuizen holed from over 40 feet for an eagle two the tournament was back in his firm grip.

With Casey making birdie it was still between the two of them, but even with the Road Hole 17th to come the outcome was effectively decided by the 348-yard 12th, innocuous by comparison.

Oosthuizen reduced it to a drive, a pitch and a 15-foot birdie putt.

Casey, on the other hand, went in gorse, took a penalty drop, was short in three, long in four and with a seven his hopes of raising the Claret Jug were buried barring a total collapse from the man he was playing with.

It was his second triple bogey of the week. The other, at the 17th in round two, was one he was able to come back from. This one will stick far longer in the memory.

Oosthuizen's only mistake on the back nine came when it did not matter, a five at the 17th.

British Amateur champion Jin Jeong took the Silver Medal after a level-par final round gave him a more than respectable four-under total for the tournament.

The Melbourne-based South Korean played brilliantly all week and was guaranteed the top amateur prize as non-professional rivals made the cut.

Jeong, who also becomes the first Korean to win the Silver Medal, will retain his amateur status until he can at least play at next year's Masters, a reward for his British Amateur success.

Oosthuizen factfile

1982: Born October 19, Mossel Bay (full name Lodewicus Theodorus Oosthuizen)

1999: Joins Ernie Els Foundation, receiving guidance and financial support from his fellow South African.

2000: Wins World Junior Team Championship with Charl Schwartzel.

2002: Wins Irish Amateur Open Stroke Play title before turning professional with a handicap of plus six.

2005: Fails to qualify for the Open at St Andrews and finishes 139th on the money list, returning to the qualifying school at the end of the season to regain his card.

2007: Wins three times in South Africa.

2010: March – Wins first tour title in the Open de Andalucia.

July – wins the Open.