On an ideal day for golf -- one that produced low scores on both the North and South Course at the Torrey Pines Club -- Levin and Stanley each fired a 10-under 62.
Levin finished 31st and Stanley was 55th on last year's money list. They both played the North Course Thursday, the easier of the two that are used for this event.
Defending FedEx Cup champion Bill Haas was alone in third at 63, having produced a round over the North Course that included 11 birdies and a double bogey.
J.B. Holmes shot a 76 in his return to tour action after undergoing surgery last year to alleviate pressure on his brain that caused extreme dizziness. Holmes, a member of the victorious 2008 U.S. Ryder Cup team, did not have a birdie on his card.
Defending champion Bubba Watson shot 69. Mark Wilson, who won last week at the Humana Challenge, is not playing this week.