New South Welshman Matt Jones sits just one shot off the lead midway through the opening round of the US PGA tour event at Riviera Country Club.

Jones fired a tidy four-under-par 67 on the iconic Los Angeles layout to sit in a tie for second just one shot behind big hitting American Dustin Johnson who’s 66 led the way after the morning wave.

Americans Robert Garrigus, Scott Stallings and Charley Hoffman plus Italy’s Francesco Molinari joined Jones a shot off the pace.

The 33-year-old Australian shot out of the blocks with back-to-back birdies to start the day but dropped a shot back with bogey on the eighth.

His birdie on the 11th was cancelled out by a following hole bogey before he stormed up the leaderboard with a fast finish.

Birdie putts of 23, 13 and six feet dropped on holes 15, 16 and 17 and his 22-foot effort on the last to tie the lead barely missed on the high side.

John Senden, playing in the first group of the day, knocked out a solid even par round of 71.

The Queenslander opened with a birdie but dropped back level with the card after a bogey on the 14th to sit mid-field.

Former winner Robert Allenby also opened with a birdie but found himself three-over through 10 holes after four bogeys.

The 2001 champion rescued his round with a flourish, making three straight birdies on 16, 17 and 18 to also finish with a 71.

Fellow veteran Stuart Appleby (72) had similar travails, opening with a birdie, but posting five bogeys in the next nine holes before clawing his way back with four birdies in a six-hole stretch.

A final hole bogey undid some of the late polish.

Former US Open champion Geoff Ogilvy struggled to a round of 74 after opening his day with a double bogey.

Marc Leishman, Greg Chalmers, Aaron Baddeley and Steven Bowditch are all due out in the afternoon wave.