Goosen fired a 66 Saturday, which was good enough to extend his lead to three strokes over a hard-charging Adam Scott, who is searching for the second win of his young professional career.
Through 54 holes, Goosen stands at 16-under-par 197 entering the last day.
Following an outward half of 2-under 34, the big South African and winner of this years U.S. Open Championship birdied the par-3 11th and sank a 15-footer for eagle at the par-5 13th, before giving a stroke back No. 16, when he pushed his drive into the right rough.
However, the 32-year-old displayed the same kind of nerve which led to his win at Southern Hills last month, as he stuck his approach to 10-feet at the finishing 18th, and then canned the birdie putt.
After the U.S. Open, if I could come back and win again that would be great, said Goosen following his round. 'I'm hungry to win again, and again, and again. I don't think I would be in this position if I weren't keen to win.'
For Scott, it seemed the round might be a bust in its early stages, as the 22-year-old Australian was 1-over through his first eight holes of the day.
But then, the youngster got it turned around in a hurry, birdying the par-4 9th and then holing a bunker shot for another birdie at the eleventh.
An eagle at No. 11 and one final birdie at the 15th gave him a very nice 67 and outright second at minus-13.
If I win or if I don't, I'll still learn something, Scott claimed of Sunday.
In joint third at 11-under resides the always-interesting name of John Daly.
Daly, the former Wild Thing and 1995 British Open champion, shot a beautiful round of 66 Saturday, which included an eagle chip-in at the par-4 9th after he nearly drove the green.
He is tied at the mark with Irishman Paul McGinley, who shot 67.
Last weeks winner of the European Open Darren Clarke fired a nice round of 68 to end tied for fifth at 9-under with Niclas Fasth (66), Barry Lane (69) and Thomas Bjorn (69), while Jesper Parnevik is a shot further back following one of the best rounds of the day, a 65.
Full-field scores from the Scottish Open at Loch Lomond