Rory McIlroy recovered from a poor start to record six birdies and earn a one-shot lead after the second round of the $6m Honda Classic in Palm Beach Gardens, Florida.
The Northern Irishman, who had been one ahead overnight after opening with a flawless 63, remained mentally upbeat despite two early bogeys and his positive attitude was rewarded with a four-under-par 66 at PGA National.
"It's just another 36-hole lead," McIlroy told reporters after posting an 11-under total of 129, one ahead of Zimbabwean Brendon de Jonge (64) and three clear of American Russell Henley (68) on a day of contrasting fortunes for the big names.
Masters champion Adam Scott, who played with McIlroy for the first two rounds, made two double bogeys on the way to a 69 as he fell eight eight shots off the pace.
World number one Tiger Woods continued his recent struggles, making the cut with nothing to spare at even-par 140 after carding a 69, while Phil Mickelson will have the weekend off after shooting a 71 for a one-over total.