Jon Rahm opened up a four-stroke lead after the third round of the Memorial Tournament on Saturday.
The Spaniard produced the equal best round of the day at Muirfield Village in Dublin, Ohio, carding a four-under 68.
Rahm sits at 12 under and is four shots clear of Ryan Palmer (73) and Tony Finau (73) as players again found scoring difficult.
World number two Rahm is on track for his first victory of 2020, having not finished in the top 25 in four events since the PGA Tour season resumed after the coronavirus-enforced break.
He was even through 12 holes in his third round before going on a run of four straight birdies beginning at the 13th, and the 25-year-old is primed to move top of the world rankings.
Finau endured a rollercoaster round that included double bogeys at 12 and 17.
Danny Willett (70) is outright fourth at six under, a shot ahead of Jason Day (72) and Henrik Norlander (71), while Matt Wallace (70) and Chez Reavie (74) are at four under.
World number one Rory McIlroy (72) and Jordan Spieth (74) appear too far back to challenge, sitting at two under and in a tie for 12th.
Justin Thomas slipped further back after a three-over 75 – now sitting at even par.
Tiger Woods, a five-time winner of the tournament, bounced back from his 76 with a 71 to climb into a tie for 37th and be at two over.