Leading first-round scores on Thursday in the US PGA Tour Byron Nelson tournament at TPC Craig Ranch in McKinney, Texas (USA unless noted, par-72): 63 - JJ Spaun, Jordan Spieth 64 - Rafa Cabrera Bello (ESP), Aaron Wise, Doc Redman, Joseph Bramlett 65 - Ben Martin, Seamus Power (IRL), Charl Schwartzel (RSA), Luke Donald (ENG), Sergio Garcia (ESP), Sam Burns, Mark Hubbard, Jhonattan Vegas (VEN), Alex Noren (SWE), KH Lee (KOR), Charles Howell, Michael Gligic (CAN) 66 - Marc Leishman (AUS), Sebastian Munoz (COL), Brandt Snedeker, Padraig Harrington (IRL), Adam Schenk, Roger Sloan (CAN), Jonas Blixt (SWE), Bo Hoag, Scott Brown, Wyndham Clark, Kim Si-woo (KOR), Ted Potter, Rhein Gibson (AUS), Kris Ventura (NOR), Dylan Meyer afp