PERTH -- South African Ernie Els continued his domination of the $1.5 million Heineken Classic at The Vines resort with a third round of 69 on Saturday to keep Sweden's Jarmo Sandelin at arm's length.

After earlier rounds of 65 and 66, Els is at 16 under par 200, three shots clear of Sandelin while young Western Australian Jarrod Moseley is five shots from the lead and Bernhard Langer a further shot back.

Nothing is certain in golf, but it is hard to see anyone in Perth this week preventing him winning his second tournament of the year.

Langer, the best credentialled if not the best placed, of his challengers virtually conceded that the horse had bolted and the other players near the top of the leaderboard agree they will have to produce something very special to catch him tomorrow.

For the second time in three days, the 6,942-metre layout was played in still conditions, but the best score for the day was only 68, five shots outside the course record set by Padraig Harrington in 1996.

"Conditions were perfect," said Els, "but I was not able to hit close to the pins. I was not in serious trouble, but both my caddie and I were amazed that no one had shot a low score. I think the pin positions were quite a bit harder. I don't know what will happen tomorrow. I will try to play as well as I can and see what the others do.

"I can only control my own golf. If someone shoots 65 to beat me, well, that is golf. But I have a three-shot lead and things are looking pretty good. If the winds blows, things could change. I remember shooting 71 last year in the final round and almost getting myself into contention."

Sandelin made a good start with four birdies in five holes from the third, let it slip with bogeys on nine and 11, but finished with a flourish with an eagle at the par-5, 473-metre 18th. There he unleashed a 300-metre tee shot with his broomstick driver which has a shaft 20 centimetres longer than normal, hit a soft 7-iron over water to the green and rolled in a putt of two metres.

"If I play like I did early in the week, I have a shot," he said. "If I play like I did in the second round (71) when I was not so steady, I have no chance. Ernie is going to shoot 67 or 68. I shot 63 with a bogey at the Lancôme last year. If I can get it going, who knows? But the main thing I need against Ernie Els is a lot of magic."

Moseley, a member of Australia's winning Eisenhower Cup team in 1996, is still looking for his first win as a pro. Last year he finished second in the Open Championships of Fiji and Samoa but he acknowledges that this is a big step up in class. "It is going to be tough," he said. "I picked up a place (from equal fourth overnight to outright third) and I'd like to move up another spot tomorrow.

"I'd like to be starting the final round a little closer to Ernie. We'll see what happens but I would be very happy to finish with four rounds in the 60s."

Langer started poorly, making an uncharacteristic bogey from the middle of the first fairway when he missed the green with a 7-iron. He got the shot back on the next hole and narrowly missed his eagle putt at the last.

"I have played solidly this week, but I missed four putts that I should have made on the first day and two more each day after that," he said. "I think Ernie is a bit far in front and he is playing really well. I'll give it my best shot and see what happens."

He was seven behind going into the final round of the 1984 Spanish Open and beat Howard Clarke by two shots with a closing, 10-under-par 62. His 12-under 60 in the 1997 German Masters was "not too shabby either," he said, but producing such low scoring again is a tall order.

"It is possible," he said. "Conditions here are very good. But you would have to play extremely well. The greens are severe and they can tuck the pins away."

The shot of the day came from Norway's Per Haugsrud who had a hole-in-one on the par-3 fourth hole. He hit a 4-iron 208 metres into the cup for no reward. If he had achieved the feat on the 13th hole he would have won a Jaguar sports car while the local casino is offering $100,000 in gaming chips at the 16th. The casino is also offering $500,000 in cash for a double eagle at the 517-metre, par-5 18th where Ernie Els on Friday hit a huge drive and got home with a wedge. Haugsrud had a round of 68 to move to 7-under-par and trail Els by nine shots.