Collin Morikawa held the lead after nine holes of the final round at The Open as Louis Oosthuizen slipped back on Sunday.
Morikawa, the 2020 US PGA Championship winner, reached the turn 14 under overall as the American moved four strokes clear of overnight leader Oosthuizen, with Jordan Spieth now his closest rival.
South African Oosthuizen is eyeing a wire-to-wire triumph at Royal St George's, where he and Spieth are each looking to lift the Claret Jug for a second time.
Oosthuizen won it in 2010 at St Andrews, while Spieth – who was 11 under through 10 – triumphed at Royal Birkdale in 2017.
It would be a bitter pill to swallow for Oosthuizen should he miss out in Kent, as he has already endured two runner-up finishes in majors this year and six in his career.
Jon Rahm got himself into the mix at eight under through six before giving a stroke back, with Corey Conners, and Dylan Frittelli on the fringes.
Four-time major winner Brooks Koepka carded a final-round 65 to close on eight under, leaving him to lament Saturday's 72.
"It's definitely a missed opportunity," he said. "I didn't play good enough on Saturday. Doesn't really matter what I finished today. I didn't have a chance to win. That's disappointing."