Only three shots separate the top 20 at the halfway stage of the RBC Heritage in Hilton Head, South Carolina.
World number one Jason Day is in a three-way share of the lead on six-under-par with American pair Kevin Chappell and Charley Hoffman.
British duo Luke Donald and Russell Knox, who shot a week-best 65, are two of three players a shot back on five-under.
Australian Day is seeking his third PGA Tour title of the season having triumphed in back-to-back tournaments last month before failing to really contend at The Masters last week.
Englishmen Paul Casey and Matt Fitzpatrick had strong finishes in the first Major of the year, but they both missed the cut by one shot with a two-round score of three-over.
