Sam Saunders, grandson of golf great Arnold Palmer, got off to a strong start at Riviera Country Club Thursday where he's in search of a first US PGA Tour title. Saunders fired seven birdies in a seven-under-par 64 to seize a two-stroke lead over US Open champion Dustin Johnson and four other players in a round delayed by fog and halted by darkness. World No. 3 Johnson, who has a chance to topple Australian Jason Day from the top of the rankings with a win this week, had six birdies and a bogey in his 66. Day was among 48 players still on the course when darkness fell and was even through 16 after four birdies and four bogeys. Two-time major winner Jordan Spieth was two-under through 16 and world number five Hideki Matsuyama — who like Johnson could possibly seize the No. 1 ranking with a win, was one-under through 16. The first round was scheduled to resume at 7 am (1500 GMT), with the second to start shortly thereafter, if predicted rain storms don't intervene. Saunders, 29, took center stage in October with a moving eulogy at a memorial service for Palmer, who died on Sept. 25 at the age of 87. While he once may have felt pressure to escape from Palmer's shadow, that's a burden he no longer carries. While Saunders is playing Riviera for the first time, Johnson is after a win on a course where has come close several times, including a 2015 playoff loss to James Hahn. Johnson's round was enlivened by a bee sting on the green at the first hole, his 10th of the day. He responded with birdie putts of 24 and 31 feet at the second and third. He was tied with newcomer J.T. Poston, Daniel Summerhays, Brett Stegmaier and Australian Cameron Percy, who birdied 18 for a share of second shortly before darkness fell. Five-time major winner Phil Mickelson headed a group on four-under 67. He was joined by Australia's Marc Leishman, Ireland's Padraig Harrington, South Africa's Branden Grace, South Korea's An Byeong-hun and Americans Billy Hurley, Pat Perez and Kevin Na. Rumford 2 shots clear Australia's Brett Rumford opened up a two-shot lead after the second round of World Super 6 Perth as former winners Thorbjorn Olesen and Louis Oosthuizen made their moves at Lake Karrinyup Friday. Perth native Rumford followed up his opening 66 with a 65 to get to 13-under and lead from countryman David Bransdon with another Australian Steven Jeffress a further shot back in the European Tour event. Rumford had shared the overnight lead with Englishman Mark Foster, who dropped back to five under after a second round 73. While Rumford looked the one to beat in the new format Super 6 event, South African Oosthuizen and Dane Olesen kept in contention. Oosthuizen, the 2011 British Open winner and three-time major runner-up, carded a four-under 68, while Olesen had a five-under 67 to lurk six strokes off the halfway lead. The top 24 players after Saturday's third round will progress to the six-hole match play knockout phase, with the top eight of those receiving a bye into the last-16. Rumford is in a comfortable position to make it into Sunday's final day. — Agencies