Dougherty, seventh in June’s US Open, has strung together a series of top-10 finishes on the circuit this season but has been frustrated by his failure to capture a second European Tour crown.

The former Walker Cup star had the Italian Open in his grasp back in May but, after forging a three-shot lead with nine holes to play, slipped to a pair of crippling bogeys on the run-in and fell back to third.

Having thrust himself to the front with a bogey-free round at St Andrews, Dougherty insisted he will adopt the policy of attack being the best form of defence as he strives to seal a long overdue success.

“Looking back to the Italian Open I think I tried to just stay in front which really was a rookie mistake,” he said.

“I tried to protect my lead and not make errors and that was not the right strategy.

“I’m going to go out in the final round and try and shoot a great score and if I can do that then I will be very hard to catch.

“To score 66 at St Andrews, a course which I haven’t really done that well on over the years, has given me a huge lift in confidence.

“I’m relaxed and not feeling worried about being in front and that is pleasing.”

Nearest challenger Peter O’Malley, who equalled the Carnoustie course record with a 64 during Friday’s second round, carded a three-under 69 at the Old course for a 14-under total of 202.

The 42-year-old, a three-time tour winner, was forced to hack out backwards from the sand at the infamous 17th – his eighth – on his way to a costly double bogey, but repaired some of that damage with four birdies over his remaining 10 holes to stay in the hunt.

Paul Lawrie, the Dunhill Links winner in 2001, made a rousing return to Carnoustie – scene of his 1999 Open triumph – and moved into a share of third on 13 under with a course record-equalling 64.

The 38-year-old from Aberdeen, who opened his challenge with a 66 then slipped back with a 73 on Friday, roared back to form with nine birdies to record his best score since he had a 64 in the opening round of the HSBC Champions tournament back in 2005.

Open champion Padraig Harrington, the winner of the Dunhill title both last year and in 2002, kept alive his hopes of a third victory as he joined Lawrie on 13 under by posting a five-under 67 at Kingsbarns.

Justin Rose, second behind Harrington on the Order of Merit, fired a 66 at Kingsbarns to join the 13-under group which also includes the 2005 Italian Open winner Steve Webster.

Former Open champion Ernie Els and Swedish duo Peter Hanson and Niclas Fasth share seventh on 12 under while Irish teenager Rory McIlroy, making only second professional appearance, almost joined that group until he stumbled to a bogey on his final hole at Kingbarns.

The 18-year-old former European amateur champion signed for a 67, which included a quartet of birdies on his first four holes, to finish the day in a tie for ninth on 11-under.

British Masters champion Lee Westwood, the Dunhill Links winner in 2003, missed the cut by a stroke on four-under despite a 68 at Kingsbarns while Ulster’s Darren Clarke also exited on four under after a 74.

Colin Montgomerie, the eight-time European number one and winner here in 2005, was another casualty as he slithered to a 74.