US PGA Tour: Padraig Harrington continues to struggle with his game after another underwhelming performance in the Californian sunshine today. The world number three, who missed the cut last weekend in Pebble Beach, carded a one-over par round of 72 at the Northern Trust Open in Los Angeles.

That leaves the Dubliner nine adrift of clubhouse leader Phil Mickelson (eight-under), who shook of his own early season lethargy to record a blemish free 63 at the Riviera Country Club.

Starting on the 10th tee, Harrington got into red figures with an early birdie at the par 5 11th hole but with a cold putter dropped three shots before the turn. Ill at ease with his long game, there were further bogeys at the 2nd and 3rd for the reigning British Open and US PGA champion but three birdies on the front nine brightened up his card.

Mickelson, on the other hand, opened the defence of his title with little sign of the problems he has experienced in recent weeks.

The left-hander has struggled for accuracy off the tee in his first three events this year but found almost half of the fairways and didn’t drop a shot. Needing only 22 putts, Mickelson leads by one from fellow American Scott McCarron.

Japanese schoolboy sensation Ryo Ishikawa, meanwhile, finished on two-over on his US PGA Tour debut.