|RBC Heritage second-round leaderboard|
|-16 S Cink (US); -11 C Conners (Can); -10 E Grillo (Arg); -9 C Morikawa (US), S Im (Kor), C Smith (Aus), B Horschel (US)|
|Selected others: -7 M Fitzpatrick (Eng); -5 R MacIntyre (Sco), I Poulter (Eng), M Wallace (Eng), D Johnson (US); -3 L Westwood (Eng), T Lewis (Eng), T Hatton (Eng), D Willett (Eng)|
Stewart Cink holds a five-stroke lead at the RBC Heritage after posting the 36-hole record at Harbour Town.
The 47-year-old heads into the weekend in South Carolina at 16 under par after back-to-back rounds of 63.
That beats the previous halfway record shared by Phil Mickelson (2002) and Jack Nicklaus (1975) by three shots.
The American made six birdies and an eagle and has not dropped a shot since his opening hole on Thursday, to lead from Canada's Corey Conners.
Emiliano Grillo is at 10 under par, with Americans Collin Morikawa and Billy Horschel, Australia's Cameron Smith and South Korea's Sungjae Im a further shot behind at nine under.
Matt Fitzpatrick sits at seven under after a 64 on Friday, with fellow Englishmen Ian Poulter and Matt Wallace two behind him alongside Scotland's Robert MacIntyre.