Brendan Steele carded a three-under-par 67 to earn a one-stroke lead after the second round.
Tom Lewis and Harris English – both competing on sponsor exemptions – carded four-under-par 66s in Palm Beach Gardens, Florida on Thursday.
American golfer Matt Kuchar set the pace in California on Thursday.
The European Tour cited fears over safety as the Hong Kong Open was postponed on Wednesday.
On a day when several of his rivals went backwards, Matthias Schwab pulled further clear in Turkey in pursuit of a maiden European Tour win.
Danny Willett is part of a four-man group sitting one shot behind Turkish Airlines Open leader Matthias Schwab.
Justin Rose is just two shots behind leaders Matthias Schwab and Tom Lewis as he eyes a third consecutive Turkish Open triumph.
Tapio Pulkkanen leads the Italian Open, with Justin Rose close behind, but Francesco Molinari has work to do.
Matthew Southgate ran him close, but Victor Perez would not be denied at the Alfred Dunhill Links Championship.
The third leg of the Alfred Dunhill Links Championship saw Victor Perez and Matthew Southgate end the day on top of the leaderboard.