Published: Sep 17, 2011 9:02 PM EDT
Updated: Sep 18, 2011 6:31 AM EDT

LEMONT, Illinois (AP) - Justin Rose pulled away Saturday with a 2-under 69 to take a four-shot lead in the BMW Championship.

Even as Cog Hill began to play more difficult under mild sunshine, Rose made only one bogey as everyone around him began to fold. He saved par on the final hole with an 8-foot putt to stay well clear of John Senden of Australia.

Mark Wilson started the third round tied for the lead but had a 77. Wilson still had to discuss a bunker situation with rules officials in which he grounded his club in the sand.

Geoff Ogilvy gave himself a good shot at two cups - the FedEx Cup and the Presidents Cup - with four birdies on the back nine for a 68 that left him five shots behind. He was tied for third with Bill Haas, who made a double bogey on the 16th but still shot 69.