World number two Phil Mickelson carded a seven-under-par 64 to take a four-shot lead over Australian Robert Allenby after the second round of the Northern Trust Open. The left-hander posted nine birdies and two bogeys as he raced to 10 under par at the Riviera Country Club in California, leaving his rivals trailing in his wake. Seven years after winning this tournament in a playoff, Allenby, though, finds himself in contention once again as he ended the second round at six-under overall alongside Americans Jeff Quinney and Vaughn Taylor. There&aposs a six-strong group in a tie for fourth at five-under, including Irish Open Champion Padriag Harrington, while Korean first-round leader K.J. Choi slipped off the pace somewhat, posting a two-over 73 on day two to be six strokes adrift of Mickelson. Allenby, however, was the pick of the Australians, with the Victorian posting a five-under 66 on Friday (US time), picking up six birdies along the way to go with a bogey on 12, his only blemish for the round. He is three strokes ahead of the next best placed Australian in Australian PGA Championship winner Peter Lonard, who managed four birdies and three bogeys on his way to a score of 70 that puts him at three under overall, alongside compatriot Start Appleby (70). Adam Scott enjoyed an impressive round, putting on three birdies in a row from the 11th to 13th holes after starting on the back nine on his way to a two-under 69 score that saw him finish the round in even-par overall alongside Nathan Green (70). Aaron Baddeley posted a solid one-under 71 on the second day to be at one-over overall, 11 strokes behind Mickelson and one ahead of Matthew Goggin (71). As the second-day&aposs play was suspended due to darkness, the cut has not been established, but, as it stands, Steve Elkington looks likely to just miss the projected cut of three-over after two consecutive two-over 73 rounds. A disastrous six-over 77 also saw Geoff Ogilvy drop from a first-round tie for 14th into position where he will also probably miss the cut at four-over while Mark Hensby (73, five-over overall), Nick Flanagan (74, six over) and Rod Pampling (75, six over) also look likely to miss out on playing this weekend.