By Craig Ray

PORT ELIZABETH, South Africa - Trevor Immelman celebrated his 27th birthday in style by carding a course record 63 to move into a three shot lead after the third round of the South African Open on Saturday.

South African Immelman moved to 20-under 196, well clear of countryman Ernie Els, who returned a round of 66 to move to 17-under at the Humewood Golf Course.

Sweden's Patrik Sjoland, who set the previous course record 64 in the second round, was five shots behind on 15-under after carding 69.

Briton Andrew Raitt (68) and South Africa's Retief Goosen (68) shared fourth place on 13-under par 203.

Immelman, the 2006 US PGA Tour rookie of the year, displayed the kind of form that took him to his maiden title in America this season with nine birdies in a bogey-free round.

He and Els set the tone for a potentially thrilling final round in front of huge home galleries as they traded birdies throughout the day.

Els started his round with consecutive birdies while Immelman made four consecutive pars.

But on the par-four fifth Immelman made his first birdie, which he followed with further birdies on the par-three sixth and the par-five seventh for an outward nine of 32.

He birdied the par-four 10th and the par-five 11th and completed his round with four straight birdies from the 15th.

"Any time you can shoot a good round in Ernie's presence is a fantastic feeling," Immelman said.

"My ball striking was not too good yesterday and I went on the range and had a long practice session - I smoothed a few things out.

"I called Lead (coach David Leadbetter) late last night and he gave me some advice.

"Today I kept my drives in play and kept my irons on the right side of the flags which enabled me to make aggressive putts.

"For a third day in a row my putter was really good. I managed to keep my focus really well and I didn't look at the scoreboard until the 18th tee."

Els, who is looking for his first win of the year to avoid a winless season for the first time since 1991, turned in 32 but made a bogey on the par-five 11th.

He bounced back a birdie on the par-four 13th and an eagle on the par-five 15th after a stunning five-wood approach to the green. He added a further birdie on the par-four 16th.

"My wedges were terrible today, that was just ridiculous," Els said in a television interview.

"But hats off to Trevor today; 63 is a great score. I know I shot 66 but it feels like I shot 75 compared to the way Trevor played."