Vijay Singh has carded a round of 66 at the BMW Championship to lead the tournament at the end of Friday's play.
The Fijian's impressive six-under score in Indiana included four consecutive birdies around the turn, with the former world number one only recording one bogey.
Rory McIlroy, who had a share of the lead overnight, is a shot further behind Singh in a tie for second with American duo Tiger Woods and Ryan Moore.
Lee Westwood's round of 65 means that he is only two shots behind Singh, but a par effort from Luke Donald has caused him to fall away from the chasing pack.
