Si Woo Kim lost all of the five-shot lead he built while flirting with sub-60 history at the CJ Cup Byron Nelson.
But the 30-year-old South Korean still managed to maintain an edge over a couple of major champions, including hometown favourite and defending champion Scottie Scheffler, heading into the final round.
Kim shot three-under 68 on Saturday for a two-shot lead over top-ranked Scheffler and 2023 US Open champion Wyndham Clark, who had matching 65s.
"I was thinking about too much scoring like first 10, 11 holes," Kim said. "So I'm just trying to be back to kind of like yesterday. Yeah, just trying to hit the good shots and trying to like, all the mojo's back."
Sungjae Im, Kim's countryman, followed a second-round 61 with a 67 and was another two shots back with Stephan Jaeger and Tom Hoge. Jaeger's 64 was the low round of the day at the TPC Craig Ranch, and Hoge shot 66.
Zach Bauchou (66) was 16 under, one shot ahead of Brooks Koepka (66) and three others. Koepka, who opened with a 63, is looking for his first win since returning to the PGA Tour from LIV Golf.
Kim, the field's second highest-ranked player behind Scheffler at No 24, was in position for a 59 in the second round but had a bogey at 18 that forced him to settle for 60.
His five-shot lead was tied for the second-biggest on tour through 36 holes this season behind Rory McIlroy's six-shot edge when he defended his Masters championship in April.
Three bogeys in a span of four holes - all on putts inside 10 feet - dropped the four-time tour winner into a tie with Clark at 18 under. Clark had earlier pulled within a stroke with a short eagle putt on the par-five ninth.
Clark took the lead a scrambling birdie at the par-five 12th, making a 15-foot putt after a bunker shot with his right foot in the grass, his flexed right knee almost touching the ground.
"It's fun being in contention," said Clark, a three-time tour winner seeking his first victory since Pebble Beach in 2024.
"Whether you have to shoot eight under to win or one under to win, it's fun because you still feel the same heat. Tomorrow it's probably going to be exactly that way where you have to make a ton of birdies."
Kim, Scheffler and Clark were tied at 19 under when Kim went in front with a birdie on the short par-four 14th after Scheffler and Clark settled for pars after trying to drive the green.
Clark got even again, but Kim went in front for good with a birdie at the par-three 15th.
Scheffler, a four-time major winner who ran away to an eight-shot victory at last year's Nelson, answered his first bogey of the tournament on the par-three fourth with three birdies over the final five holes on the front nine.
Jordan Spieth, a hometown favorite alongside Scheffler, faded with four bogeys on his first five holes on the back nine a day after six consecutive birdies to start his second nine spurred a 62. He shot 73.
First-round leader Taylor Moore was back in contention after four consecutive birdies, but went in the water at the 15th and ended up with a triple-bogey 6. He shot 69 and was 13 under.
Watch the The CJ Cup Byron Nelson live until Sunday on Your Site Golf, where Scottie Scheffler is the defending champion. or .
