Pre-tournament favourite Adam Scott shot a flawless 65 to build a commanding lead over his rivals after a rain-soaked second round of the Scottish PGA Championship.

Scott sits atop the leaderboard with a 12-under-par halfway total of 132 and a four-shot lead over Australian compatriot Richard Green.

Wet conditions greeted the early starters at Gleneagles on Friday, in stark contrast to the sunshine which bathed the Centenary Course the day before.

Greenkeeping staff were out in force to clear the putting surface to allow play to continue, after water began to collect on the course.

But Scott coped well with the conditions to move into the outright lead.

The 22-year-old's first-round 67, which culminated with an eagle three on the 18th, left him two behind overnight leader Green.

But while left-hander Green made two bogeys in his first three holes, Scott, starting on the 10th, opened with two pars before a birdie on the par-five 12th took him to six under.

Further birdies at the back nine's other two par fives, the 16th and 18th, took Scott to eight under par - good enough for a two-shot lead.

Four more birdies followed on the front nine to take Scott four shots clear of the field.

Spain's Ignacio Garrido had briefly closed the gap to one shot before running up a triple bogey seven on the first, eventually coming home in 71 for a six-under-par total.

Green picked up shots at the 12th and 14th to remain Scott's closest challenger. The 31-year-old Australian finished the day eight under.

Scott Gardiner, another Aussie, moved to seven under par with six holes to play on Friday.

Sharing third place with Gardiner, with a few holes to play, are Welshman David Park and Scotland's Sam Torrance.

England's Matthew Cort, Ireland's Philip Walton and Sweden's Fredrik Andersson are in the clubhouse on six under par.

Joining that trio on six under, but yet to complete their second rounds, are Scotland's Andrew Oldcorn, Norway's Henrik Bjornstad and Germany's Marcel Siem.

12 under: Adam Scott (Aus) (after 36 holes)
8 under: Richard Green (Aus) (36)
7 under: Scott Gardiner (Aus) (30)
David Park (33)
Sam Torrance (34)
6 under: Ignacio Garrido (Spa) (36)
Matthew Cort (36)
Fredrik Andersson (Swe) (36)
Philip Walton (36)
Marcel Siem (Ger) (30)
Henrik Bjornstad (Nor) (34)
Andrew Oldcorn (34)