Alex Noren collected five birdies over the back nine holes to take a 2-shot lead at the Nedbank Golf Challenge in South Africa on Friday as European Tour money list leader Henrik Stenson fell off the pace.

Noren, the tour's form player who is seeking a fourth title this season, shot a 5-under 67 at Sun City to move 8 under overall after two rounds.

Five players, including former British Open champion Louis Oosthuizen, are two shots behind Noren.

Stenson was one off the lead after the opening round but found the going tougher on Friday with three bogeys on the front nine and a double-bogey seven on the back. Seeking the victory that could wrap up the Race to Dubai, Stenson carded a 2-over 74 for 1 under overall and a tie for 17th.