US Open champion Webb Simpson moved to the top of the USPGA Tour Greenbrier Classic leaderboard on Friday, while Tiger Woods and Phil Mickelson were projected to miss the cut in West Virginia.

Simpson followed up his opening 65 with a bogey-free 66, and led the way by one shot on nine under when play was suspended due to darkness with 12 players still on the course.

Rookie Charlie Beljan carded an eight-under 62 for a share of second place along with Jerry Kelly, Jeff Maggert and Jonathan Byrd, with Martin Flores on the same score after 16.

JB Holmes (68) and South Korea's Charlie Wi (66) were a further stroke back in a tie for seventh.

Woods, meanwhile, finished level par after carding a 69 and Mickelson's second straight round of 71 left him two over. The projected cut was one under.

Overnight leader Vijay Singh slipped off the pace after following up his first-round 63 with a disappointing 74.