Brett Rumford, the overnight leader, bogeyed his last hole on Friday to shoot a 2-over 74. He is tied for fourth place with Stephen Dodd, who carded a 73, at 6-under-par 138.
Forsyth opened on the back nine Friday and notched back-to-back birdies from the 16th. He reached the green in two at the par-5 third and two-putted for his third birdie of the round.
The Scotsman seemed poised to drop his only shot of the round at the ninth hole, his last in the second round. Forsyth had 15 feet for par but calmly sank the putt to preserve his bogey-free round.
'It is a course that if you are playing well it does offer you chances,' said Forsyth, who won the 2002 Malaysian Open. 'I didn't take them all today and to be honest I still feel the putting is a little bit rusty after the winter lay-off but I am sure that will come in time.'
Lile mixed six birdies and two bogeys on Friday and both dropped shots were mistakes by the South African. He three-putted from 10 feet at the fourth and bogeyed the par-5 16th when he had only 80 yards with his third shot.
Lile overcame the mistake at 16 with a spectacular approach on No. 17, the toughest hole on the course. He knocked a 7-iron to four feet to shoot a 4-under 68 and tie for the lead.
'I had no real expectations coming into the week, I was just hoping to make the cut to be honest which I have done obviously!' said Lile, who played on the Nationwide Tour for a time last year. 'You never know what will happen at the weekend but if you put yourself in a position to win enough times, it will eventually come.'
Van Rensburg started on the second nine and bogeyed two of his first six holes. He rebounded with a birdie at the 16th then closed with three birdies in his last seven holes to polish off a round of 70.
The 38-year-old South African seems healthy for the first time in two years after breaking a bone in his wrist.
'It is a lot better now and I am finally hitting the ball with no pain which is great,' said van Rensburg. 'I came back a little earlier than my doctor advised but I found I was trying to hit the ball and guard my right side and you can't play like that.'
Raphael Jacquelin (71), Anders Hansen (69), Stephen Scahill (72) and Simon Wakefield (69) share sixth place at minus 5.
Defending champion Trevor Immelman posted a 3-under 69 and is part of a group in 10th place at 4-under-par 140.
The 36-hole cut fell at 3-over-par 147 and 76 players made it to the weekend. Colin Montgomerie was fortunate to get there. He took a seven on the third hole and an eight on the 17th to shoot a 6-over 78 and tie for 51st at plus 2.