After his victory at Pebble Beach last week, Mickelson fired six birdies to a single bogey to lead American pair J.B. Holmes and Hunter Mahon There were still 30 players yet to complete their rounds on the Riviera course in Los Angeles when play was abandoned for the day to bad light. High winds had already slowed play and made scoring difficult.
The best placed Aussie was new dad Marc Leishman who was tied for 14th on 1-under.
Mat Goggin was the next-best Australian after and even-par 71, while defending champion Aaron Baddeley was two over along with a disappointed Jason Day, season debutant Adam Scott, John Senden, Stuart Appleby and Jarrod Lyle.
Geoff Ogilvy and Robert Allenby were a shot further back at three-over while Greg Chalmers rounded out the Aussie contingent at four-over.2012 Northern Trust Open Leaderboard