MIAMI (AFP) — South Korean Kim Si-woo fired a five-under par 66 on Saturday to seize a one-shot lead over two-time major champion Justin Thomas and Andrew Novak after 54 holes at the US PGA Tour’s RBC Heritage in South Carolina.

Kim, a four-time PGA Tour winner, had six birdies through the first 15 holes, pushing his lead to as many as three before a bogey at the par-four 18th — where overnight leader Thomas birdied to pull within one.

“I played great,” Kim said. “Only missed the last hole so that’s not a big deal. I played pretty much 35 holes really decent, so I’m not going to worry about the last hole for tomorrow.”

Kim — who says he’s trying to use his failure to book a Masters berth for the first time since 2017 as motivation, had started the day two adrift and started motoring up the leaderboard with birdies at the first and second.

He added two more at the fifth and ninth — where he got up and down from a greenside bunker — and build his lead with birdies at 13 and 15 — where he rolled in a 19-foot putt that he called his most important shot of the day.

But he was poorly positioned in the 18th fairway, his second shot landing on the bank of the hazard. He fired out to six feet, but after Thomas drilled his 15-foot birdie putt Kim missed his par effort to finish with a 15-under par total of 198.

“I’m in a good position,” Kim said. “I’ve been playing good. Especially iron play is really good for this week. Yeah, just one more day left.”

Thomas, chasing his first victory since he won his second PGA Championship crown in 2022, had four birdies, but two back-nine bogeys had him three back before his birdie at the last saw him complete a two-under 69 to join Novak on 199.

“It was huge,” Thomas said of his closing birdie. “I played really well today, really solid, just didn’t have much to show.”

The birdie capped an eventful round that included a par at the second, where he was assessed a one-stroke penalty when his ball moved as he removed a loose impediment from a waste area.

He ended up covered in mud when he opted to play out of shallow water on the way to a bogey at 11.