Keegan Bradley shoots a 6-under 66, takes a 4-stroke lead at CIMB Classic in Malaysia

Keegan Bradley had five birdies in a six-hole stretch on the back nine Friday to shoot a 6-under 66 and open up a four-stroke lead over Ryan Moore after the second round of the CIMB Classic.

The American started the day in second place behind Moore after an opening-round 65 and is now at 13-under 131 for the tournament, an official event on the PGA Tour for the first time. He has one bogey in 36 holes.

Moore had three bogeys to go with three birdies in a 72 and sits at 9-under, a stroke ahead of Thailand's Kiradech Aphibarnrat and American Chris Stroud.

A day after saying his swing was as bad as it's been "in a long time," Phil Mickelson again struggled with some wayward drives and shot a 2-under 70. He's 10 shots off the pace.