Webb Simpson fired a 63 to leave himself just one shot back of leader Jimmy Walker at the halfway stage of the Wyndham Championship.
Herron matches Pettersson's course record with round of 61
Webb Simpson fired a 63 to leave himself just one shot back of leader Jimmy Walker at the halfway stage of the Wyndham Championship.
Reigning champion Simpson managed to birdie four of his last five holes in his bogey-free round to move to 11 under for the tournament.
However that still wasn't good enough to put him on top, fellow American Walker going even better with an eight-under 62 to sit clear at the summit.
He picked up shots at the second and third at Sedgefield Country Club, and went to the turn in four-under before closing his round with three birdies in the last four holes.
A group of four players are tied on 10-under including Spaniard Sergio Garcia (63), Tim Clark of South Africa (67) and Harris English, who signed for a 64.
Recovery
The trio are joined by first-round leader Carl Pettersson, the Swede recovering from two-over after eight holes with two birdies around the turn and an eagle at the par-five 15th.
Pettersson - a member at the club - saw his course record of 61 tied as veteran Tim Herron recovered from an opening 76 to go 15 shots better and make the cut.
The American, who covered the back nine in just 29 shots, had begun the second day lying 155th in the 156-man field, but surged up the leaderboard and into a tie for 41st place on three under.
Early contender David Mathias slipped off the pace, adding a 71 to his first round 63 - a triple bogey seven at the 11th doing much of the damage.
American duo Matt Every and Bud Cauley were nine under at the midway mark, with compatriot Troy Matteson and Belgium's Nicolas Colsaerts a further shot back in the final PGA event before the FedEx Cup play-offs.
Jamie Donaldson was the best placed of the British and Irish contingent in the field in North Carolina, the 36-year-old Welshman adding a 66 to his opening 68 to join seven other players on six under - six shots off the pace.
