Rod Pampling and Greg Chalmers sit inside the top 10 after the first round at the US PGA Tour event at Torrey Pines.
Pampling fired an eight-under-par 64 to be tied fourth, one better than reigning Australian Open and PGA Champion Chalmers who signed for a seven-under 65, enough to be tied eighth.
Americans Spencer Levin and Kyle Stanley lead the field after producing blistering 10-under rounds of 62, one clear of Bill Haas (63) who is third at nine-under.
All but one of the top 16 players completed the easier north course in the opening round, with Marc Turnesa (66, tied 13th) claiming round honours on the more difficult south course.
The field plays on both courses over the opening two days before reverting to the 2008 US Open south course for the weekend.
Pampling flew out of the gates with an opening birdie but his form closing out the front nine was even more impressive. The 42-year-old punched out four birdies in five holes to go out in 31 shots – enough to hold the solo lead for a brief moment.
He finished his round with three further birdies on the back nine to post a career-low score on the north course.
It was the first time in nine attempts he had broken 70 in his opening round at the event, although he twice previously shot 67 in second rounds on the north.
Chalmers raced out of the blocks with three birdies in his opening four holes.
He followed up with two further birdies before dropping a 50-foot bomb for eagle on the par-five 18th.
Robert Allenby and Gavin Coles were the next best-placed Australians in a tie for 26th after posting four-under 68s on the north course, while Nick O’Hern was the pick of the Aussies on the south.
O’Hern muscled his way to a three-under-par 69 on the trickier side of the course to be tied 36th. Aaron Baddeley (-2, NC), Stuart Appleby (-1, NC), Geoff Ogilvy (Even, SC), Marc Leishman (Even, SC), Nathan Green (Even, NC), Jarrod Lyle (+1, SC), Steven Bowditch (+2, SC), Mathew Goggin (+3, SC) and Matthew Giles (+3, SC) rounded out the Australian assault.
New Zealander Danny Lee found himself tied for 17th after a five-under 67 on the north course.
