South Korean Kang Sung's third-round 71 was good enough for a three-shot lead on Saturday after American Rickie Fowler's late stumble at the US PGA Houston Open.
Kang, a 29-year-old chasing a first US PGA Tour title that would give him a late invitation to next week's Masters, couldn't match his sizzling 63 of Friday.
But his one-under effort for a 17-under-par total of 199 still left him a slight cushion going into the final round on Sunday, when weather threatened to disrupt proceedings.
Kang's round of four birdies and three bogeys helped him withstand the pressure applied by Fowler, who had eight birdies in his first 14 holes to grab a share of the lead before finishing with a bogey at 17 and a double-bogey at the last.
Fowler settled for a 67 for 202 -- one stroke in front of American Russell Henley, who signed for a 69.
Luke List was alone in fourth on 204 after a seven-under 65 that included eight birdies and just one bogey.
Kang, who started the week ranked 202nd in the world, began the round with an impressive six-shot lead, but Fowler wasted little time in eating into that.
After birdies at the third and fifth, Fowler rolled in a 47-foot putt at the seventh to ignite a string of three straight birides to cap the front nine.
His 19-foot birdie attempt at the 10th circled the cup but somehow didn't drop, but he strung together three more birdies at 12. 13 and 14 to briefly join Kang atop the leaderboard.
But he gave a stroke back at the 17th, where he was in two bunkers, then fired his tee shot well right at 18. Although he was able to find the green with his second shot, Fowler rattled his par-saving putt from inside four feet past the hole, then missed the bogey putt coming back.
Fowler's miscues offered breathing room to Kang, whose bogey at 16 had dropped him into a tie for the lead for the second time on the back nine.
The South Korean, who hasn't posted a victory since the 2013 Korean Open, had largely kept his nerve in the face of Fowler's charge, rolling in birdie putts of 20 feet at the 11th and 15th.
With possibly severe storms expected to move into the area on Sunday afternoon, tournament officials moved up fourth-round tee times in hopes of beating the weather.
At least 18 players who made the cut -- Kang could be the 19th -- are due to head from Houston to Augusta, Georgia, to begin preparations for the Masters, increasing the pressure to avoid a Monday finish.
© 2017 AFP