South Korea’s Sung Kang produced a superb nine-under-par round of 63 to take a six-shot clubhouse lead on day two of the Houston Open.
Kang, 29, carded seven birdies and one eagle, adding to his first round 65, to set a new 36-hole tournament record on 16 under.
Americans Hudson Swafford and Russell Henley are Kang’s nearest challengers on 10 under after both hit 67.
Overnight leader Rickie Fowler started his second round on eight under.
Kang is currently ranked 202nd in the world and has missed the cut in five of his nine PGA Tour events in 2017.
England’s Justin Rose began the day three shots off the lead, before shooting a one-under 71 to trail Kang by 10 strokes.