Harrington makes slow start in California

Pádraig Harrington got his season up and running with a 72 at the Northern Trust Open at Riviera Country Club near Los Angeles.

Phil Mickelson put the wedge controversy behind him but his bid for a third successive victory at the event also got off to a slow start.

Mickelson had drawn heavy criticism at last week's Farmers Insurance Open when he chose to exploit a loophole in the new rules allowing only clubs with shallow and narrow V grooves by putting in play a pre-1990 Ping Eye 2 wedge.

The row escalated over the weekend and forced PGA Tour commissioner Tim Finchem to promise to review how best to close the loophole, which arose from a legal settlement after a lawsuit brought by Ping in the early 1990s.

The three-time major winner slammed the existence of the loophole and the new regulation but said on Wednesday he would not use the Ping wedge this week 'out of respect' for his fellow professionals.

After 11 holes of his first round at the par-71 Riviera, the world number two was three under par, four shots back on clubhouse leader and fellow American Dustin Johnson.

Mickelson's round began to fall apart from there, however, with bogeys at the par-four 12th and 15th holes and then the par-three 16th as the left-hander fell back to level par. There was more woe as Mickelson, who had opened with a 63 in 2009, also bogeyed the par-four 18th to leave him with a one-over 72, eight shots behind Johnson.

Harrington had been practising with an Eye 2 wedge but opted not to put it in play, leaving only Ryder Cup player Hunter Mahan and former Masters champion Fred Couples using the controversial club. Couples finished with a two-under 69, while Mahan shot 71.

The early-starting Johnson fired a seven-under 64 to lead by a stroke from Argentina's Andres Romero.

Of the afternoon starters in Pacific Palisades, Kevin Stadler got off to a fast start at six under after eight holes, having begun his round at the famous par-four 10th. The front nine proved less productive despite a birdie at the first, with a bogey at the second followed by pars all the way home for a six-under 65.

Stadler will start the second round on his 30th birthday in a share of second place with Romero.

Americans Ricky Barnes and Brandt Snedeker were a further shot off the lead at five under with world number three Steve Stricker one of a trio at four under, along with fellow Americans Steve Lowery and Cameron Beckman after 67s.

England's Luke Donald, Japanese teenager Ryo Ishikawa, former world number one David Duval and veterans Scott Verplank and Jesper Parnevik were all part of a large group on three under.

Sweden's Parnevik carded his 68 despite a bout of sciatica.

Englishman Justin Rose finished at two under, as did newly-appointed US Ryder Cup vice-captain Paul Goydos.

Rose's compatriot Greg Owen carded a level-par 71 but Goydos' captain, Corey Pavin, fared less well with a one-over 72.