Kevin Kisner held a one-stroke lead over Hideki Matsuyama and Chris Stroud midway through their third rounds at the US PGA Championship as players struggled to get moving.
A surprise co-leader through 36 holes, Kisner was one under through nine in his third round at Quail Hollow and sat clear of the field at nine under overall.
The American, without a top-10 finish in his major career, showed no signs of nerves and had other opportunities in fine conditions.
Matsuyama, who shot a stunning seven-under 64 in the second round, hit just two fairways on the front nine but was even for the day to be a shot back.
The other member of the final group - Jason Day - was one over in his third round, leaving him four off the pace.
However, the unheralded Stroud moved into a tie for second with Matsuyama after turning in two under.
Matsuyama, coming off a bogey-free round, dropped a shot at the first – a hole at which no birdies were made in the third round – missing a left-to-right six-footer after finding the left greenside bunker.
Day joined him in a tie for second at the next hole, a brilliant approach to within four feet seeing him birdie as Kisner and Matsuyama missed chances.
Kisner created birdie opportunities on each of the first three holes, and his perfect record from inside 10 feet at this tournament came to an end when he missed from seven at the third.
Day seemingly misread a four-foot birdie putt at the fifth before opportunities predictably arrived at the par-five seventh.
Matsuyama tapped in for birdie but Kisner, who almost found the water with his second, also picked up a shot to remain one stroke clear.
Day had eagled the hole the previous two days but had to settle for par after three-putting and the Australian then bogeyed the ninth.
Louis Oosthuizen was at five under with Day, while Rickie Fowler and Justin Thomas were a shot further back.
Spaniard Jon Rahm briefly made a move on Saturday and was five under through 14 before going five over on his final four holes.
Jordan Spieth's bid for a career Grand Slam is set to have to wait, the world number two shooting a 71 to reach the clubhouse at three over.
|WATCH: Mendy and Pogba dab with president Macron after World Cup win|
|Woods embracing ´different´ Carnoustie challenge ahead of Open return|
|Argentina dismiss Sampaoli after chaotic World Cup|
|France celebrates World Cup triumph|
|Djokovic made ´improvised Wimbledon trophies´ as a boy|
|Stone goes agonisingly close to 59 as Pepperell & Dantorp also make Open|
|Outcast Benzema delights in France win|
|Final a triumph in itself given Croatia´s off-field turmoil|
|Anderson laments Wimbledon final nerves|
|Deschamps joins elite club, Mbappe second to Pele - the best stats from the World Cup final|
|Belgium´s Courtois wins World Cup Golden Glove|
|Collarbone fracture confirmed for ´devastated´ Porte|
|World Cup final player ratings: Griezmann, Mbappe inspire France as Croatia fall short|
|World Cup winner Giroud ends tournament without shot on target|
|Modric wins World Cup Golden Ball|
|Mbappe wins World Cup Young Player award|
|Deschamps redeemed as France win World Cup final for the ages|
|France 4 Croatia 2: Twitter Report|
|Tomlin optimistic over Bell contract|
|Kane wins World Cup Golden Boot|
|Ajax keen on Blind deal - Van der Sar|
|France 4 Croatia 2: Pogba and Mbappe seal thrilling World Cup triumph|
|Anderson would have played another 21 hours to reach Wimbledon final|
|Djokovic delighted to crown ´comeback´ with Wimbledon glory|
|World Cup final interrupted by pitch invaders - Pussy Riot claim responsibility|
|Djokovic´s grass-court U-turn pays ultimate dividends with Wimbledon title|
|Mandzukic makes World Cup history with early own goal|
|Dominant Djokovic beats Anderson to regain Wimbledon title|
|Everybody said I´m done - Degenkolb revels in first Tour victory|
|´Big party´ for Marquez after Sachsenring success|
|Hazard enjoys Belgium´s welcome home|
|Ex-AC Milan president Berlusconi conflicted over Ronaldo to Juventus|
|Spain did not contact Martinez over head coach vacancy|
|Maybe the VAR was watching The Simpsons! - RSL coach Petke slams MLS officials|
|Cubs´ Darvish hopes to return by next weekend|
|France and Croatia name unchanged sides for World Cup final|
|Marquez maintains Sachsenring dominance|
|Courtois claims World Cup has boosted his value|
|Buffon beaten on difficult PSG debut|
|Vince called up for Headingley decider|
|Farah inspires Tigers win over Dragons, Warriors and Roosters triumph|
|Crash forces Porte out of Tour for second year running|
|Ronaldo considered Napoli move, says De Laurentiis|
|Mafi arrested for allegedly assaulting Rebels team-mate|
|Everybody is welcome - Croatia pitch for neutral support in World Cup final|
|West Ham seal club-record swoop for Felipe Anderson|
|Rooney applauds England for capturing fans´ imagination|
|Krajicek urges Anderson to go for broke in Wimbledon final|
|Wimbledon 2018: Djokovic v Anderson in Opta numbers|
|Kohli defends Dhoni after Lord´s boos|
|Wimbledon finalist Djokovic can win the next six majors, claims Krajicek|
|We´re ´blessed´ to watch Mbappe, says Kaka|
|Bogaerts hits walk-off grand slam to deliver Red Sox win over Blue Jays|
|Cardinals dismiss Matheny, name Shildt interim manager|
|Pacquiao knocks out Matthysse to win welterweight title|
|Didulica expects ´cagey´, tight World Cup final|
|MLS Review: Rooney impresses on debut, Galaxy leave it late|
|Truex dominates to win Quaker State 400 again|
|Kim in control at John Deere Classic|
|Braves place closer Vizcaino back on DL, manager concerned about injury|
|Long on Eagles having Wentz, Foles: It´s really a dream|
|Effenberg: I´d prefer Mandzukic over Neymar|
|Courtois open to Chelsea stay amid Madrid links|
|Rays´ Ramos won´t play All-Star Game due to hamstring injury|
|Gary Sanchez injury update: Yankees catcher on track to return after All-Star break|
|Windies crush Bangladesh again to seal series win|
|Klopp backs Lovren´s lofty ´best in the world´ claim|
|Root welcomes ´ruthless´ England display|
|Martinez on target in impressive Inter debut|
|Kerber puts Wimbledon triumph down to 2017 hardships|