LOS ANGELES: Kang Sung fired three birdies and a bogey over the final nine holes of the rain-delayed third round of the US PGA Byron Nelson Sunday to regain a three-shot lead over fading Matt Every.

South Korea's Kang had taken a four-shot lead into the round when it got underway after a six-hour weather delay on Saturday, but was one back when darkness halted play.

But Every, who vaulted into the lead with an eagle and four birdies over the first eight holes, came unstuck when play resumed, his two back-nine birdies book-ending a run of four straight bogeys at 12, 13, 14 and 15 at Trinity Forest in Dallas, Texas.

Kang signed for a three-under par 68 and went into the afternoon with a 19-under par total of 194 as he seeks a first US PGA Tour title.

Every, a two-time winner on the tour, carded a 67 for 197.

American Brooks Koepka, using the tournament as a tune-up for his defense of the PGA Championship title at Bethpage Black next week, birdied three of his last five holes to card a third-round 68 and shared third place with Scott Piercy on 14-under 199.

Piercy climbed up the leaderboard with an eight-under par 63, putting himself in the hunt before final round play began on Sunday under sunny skies.