Leading scores after Thursday's first round of the US PGA Genesis Invitational at par-71 Riviera (USA unless noted): 64 - Sam Burns 66 - Matthew Fitzpatrick (ENG), Max Homa 67 - Wyndham Clark, Patrick Cantlay, Joaquin Niemann (CHI), Matt Jones (AUS), Scottie Scheffler, Tyler McCumber, Alex Noren (SWE), Jason Kokrak 68 - Dustin Johnson, Francesco Molinari (ITA), Keegan Bradley, Talor Gooch, Brooks Koepka, Sebastian Munoz (COL), Jordan Spieth 69 - Cameron Tringale, Will Zalatoris, Mackenzie Hughes (CAN), Charley Hoffman, Adam Scott (AUS), Tyler Duncan, Adam Long, Andrew Landry, Jim Furyk, Cameron Smith (AUS), Lanto Griffin, Wesley Bryan, Marc Leishman (AUS), Russell Henley, Kim Tae-hoon (KOR) afp