Stewart Cink was eyeing his third RBC Heritage title after claiming a 54-hole record by carding 69 to go with his earlier pair of 63s to take a five-stroke lead heading into the final day in South Carolina
The 47-year-old, who previously won at Hilton Head in 2000 and 2004, set a score of 18-under 195 which took two strokes off the previous record at the course set by Justin Leonard in 2002, when the former Open winner finished the third day at Hilton Head at 16-under 197.
Matt Wallace climbed 15 places on the leaderboard on Saturday into a share of fourth, seven strokes back from Cink, after the Englishman went bogey-free and collected six birdies including one on the par-three 14th hole en route to a 65.
Collin Morikawa started the day in fourth and carded a 67 to finish in second at 13-under, with Argentina's Emiliano Grillo one stroke further back in third.
Matt Fitzpatrick of England was at 10-under after carding a 68 to sit in sixth with Americans Webb Simpson and Harold Varner III as well as Canada's Corey Conners.
Englishmen Danny Willett and Tom Lewis were at seven-under and 11 strokes off the pace, while Scotland's Robert MacIntyre and Shane Lowry of Ireland nipped at their heels a further shot back at six-under after recording scores of 70 and 72 respectively.
Lowry's score saw him drop 16 places to a share of 27th.
The Offaly man had started the day four shots behind leader Corey Connors following a second-round 65 but finished it 12 behind Cink.
Lowry made three birdies but cancelled them out with two bogeys and a double after finding the water on the par-3 fifth.
Leaderboard after Round 3 @RBC_Heritage:
— PGA TOUR (@PGATOUR) April 17, 2021
1. @StewartCink (-18)
2. @Collin_Morikawa (-13)
3. @GrilloEmiliano (-12)
T4. @MattSJWallace (-11)
T4. Sungjae Im
T6. @WebbSimpson1 (-10)
T6. @MattFitz94
T6. @HV3_Golf
T6. @CoreConn
T10. 7 players tied (-9)
Ian Poulter of England had a shocking day as he bogeyed six times and double-bogeyed the par-five fifth to card a 73 and drop 28 places for a share of 47th.
And his compatriots Tyrrell Hatton and Lee Westwood just made the cut for the final day with respective scores of 73 and 75, with Westwood 19 strokes off the pace in last place.
