Spaniard Sergio Garcia has carded a second-round 64 to take the outright lead at the BMW Championship in Denver on eight-under-par.
Garcia picked up five birdies and an impressive eagle at the seventh to take a one-stroke lead over Ryan Palmer - who also shot a 64 - on seven-under.
Rory McIlroy, who spurned a two-shot lead on Thursday after bogeys on 15 and 16, learnt from his mistakes to birdie those two holes en route to six-under, level with Billy Horschel.
Meanwhile, Graham DeLaet, Bubba Watson and Hideki Matsuyama make up a three-way tie for fourth ahead of Saturday.