In a performance reminiscent of Tiger Woods' annihilation of the field at the 2000 U.S. Open at Pebble Beach, Goosen seemed to toy with a difficult course that sent many of his challengers sliding down the leaderboard.
'I'll give myself 10 out of 10. I played great,' said Goosen, who himself won the U.S. Open in 2001. 'I've shot 62 a couple of times at Loch Lomond but I would say in the conditions, and the way the course is set up, this is probably the best round I've played.'
The 32-year-old South African tallied nine birdies in a bogey-free round, including an impressive closing birdie after a patience-testing delay at the par-4 18th. He finished with a three-day total of 15-under-par 201.
Ernie Els (71) and Sergio Garcia (72) each bogeyed the last to finish the day tied for second place at 2-under 214.
Englishmen Anthony Wall (69) and Simon Dyson (70) were together at 1-under-par, while Australia's Wayne Riley (69) finished alongside Pierre Fulke (74) of Sweden at even-par 216.
Thailand's Thongchai Jaidee and New Zealand's Steve Alker, just one and two shots behind Goosen coming into the day, respectively, both struggled to find fairways and greens in round three. Jaidee ballooned to a 6-over 78 and Alker carded a 77 to join a seven-way logjam at 1-over-par.
Goosen notched four birdies on the front nine, the last with a 15-foot putt at the par-3 eighth to reach double digits under par. He took a seven-shot advantage into the back nine, then blew the tournament wide open with four birdies in the span of five holes from the 11th to the 15th.
The closest Goosen came to posting a bogey was at the par-3 17th. But even after his tee shot landed short of the green and his chip stopped seven feet short of the hole, Goosen managed to calmly roll in the putt to keep his card clean of mistakes.
The difficult conditions resulted in slow play, and Goosen had to wait at least 20 minutes to tee off at the 459-yard 18th, the hardest hole on the course. After waiting some more in the fairway, Goosen roped a 2-iron from 225 yards to 15 feet then sank the putt to complete the record round.
'I'm seeing the shots so well out there and obviously I'm reading the greens great,' Goosen said. 'I've been hitting the ball well for the last three weeks and it was only the putting which was holding me back.'
Goosen's putting has improved each day; he needed 32 putts during his first-round 70, 26 during Friday's 68 and only 25 on Saturday.
Although Goosen's 63 matched the score set by Gary Player at Lake Karrinyup in 1974, the course has been lengthened by some 300 yards since then. The previous course record on the extended layout was 65, shot most recently by Alker in round two.
The 13-shot lead produced by Goosen established a new European Tour record for largest leading margin after 54 holes, shattering the old mark of 10 strokes held by Tony Jacklin (1974 Scandinavian Enterprise Open), Ken Brown (1984 Glasgow Open) and Woods (2000 U.S. Open).
Goosen has a chance to break the European Tour and U.S. PGA Tour record for winning margin, which Woods set at 15 strokes at Pebble Beach.
Goosen, a four-time European Tour winner at this point a year ago, has been one of the world's hottest golfers since his U.S. Open victory in an 18-hole playoff at Southern Hills last June. He built on his first major title by winning the Scottish Open a month later.
After a disappointing second-place showing at the Trophe Lancme, where he was caught from behind in the final-round by Garcia, Goosen closed the season with five straight top-10 finishes, including his third triumph of 2001 at the Open de Madrid.
He ended the season with 2,862,806 euro to finish No. 1 on the Order of Merit.
So far, so good for Goosen in 2002. During the European Tour's two-event swing through his home country, Goosen tied for fifth at the South African Open and tied for second at the Dunhill Championship.
Save for a collapse of titanic proportions Sunday, Goosen will earn his eighth career victory (apart from his seven South African titles) and be well on his way to another big year.
Full-field scores from the Johnnie Walker Classic