Adam Scott has failed to make a move in the third round of the BMW Championship at Cherry Hills Country Club in Denver, leaving the Australian tilt floundering.

American Billy Horschel has produced a blistering seven under 63 to surge to 13 under for the tournament and a three-shot lead from fellow American Ryan Palmer.

US Open champion Martin Kaymer (64) and Masters champion Bubba Watson (66) share third at eight-under.

After positioning himself for a potential charge with a four-under 66 in round two, world No.2 Scott struggled for most of the day but surged late to save some face.

With three straight birdies to finish he shot 69 to be tied for 10th at four-under, a distant nine shots back of the lead.

While a victory is likely beyond his grasp the Queenslander can still push for a high finish to improve his season-long FedEx Cup ranking heading to next week’s tour championship, increasing his chances at winning the US$10 million bonus.

John Senden (70) sits one-under par and tied 23rd as the next best Australian while Geoff Ogilvy (+1), Stuart Appleby (+2), Marc Leishman (+2), Matt Jones (+6) and Steven Bowditch (+9) continued to struggle.

Jason Day withdrew with a back injury during the second round.