Rory McIlroy exorcised his Friday demons in style at the 143rd Open Championship as he carded a second consecutive 66 to finish on 12 under par, four shots clear of nearest pursuer Dustin Johnson.
McIlroy has made an unfortunate habit of following good rounds on Thursday with bad ones on Friday in 2014, the latest example being scores of 64 and 78 in the Scottish Open last week.
In total he was 50 under par in the first round and nine over par in the second this year until carding seven birdies and just one bogey on Friday to boost his chances of becoming only the third player in the modern era - after Tiger Woods and Jack Nicklaus - to win three majors by the age of 25.
It is the first time McIlroy has led at halfway in a major since the 2011 US Open, when he went on to win his first major by eight shots after rewriting the record books at Congressional.
And by getting the benefit of the best conditions with early-late tee times it made amends for leading the 2010 Open at St Andrews with an opening 63 only to follow it with an 80 in atrocious conditions.
McIlroy could have been forgiven for fearing the worst when he bogeyed the first hole after overshooting the green, but with the wind dropping he regained the lead with a two-putt birdie on the fifth and moved two ahead with another birdie on the sixth.
Even the distraction of a pheasant wandering across the eighth green as he lined up another birdie putt failed to prevent McIlroy from picking up another shot, while he also birdied the 10th before surprisingly missing from four feet on the 11th.
The Northern Irishman did then hole from that distance on the 15th after a superb tee shot and a drive of almost 400 yards on the 17th set up another, while he pitched to four feet on the last to end in style.
Johnson shot the round of the week so far with a 65 to lead the chase on eight under and will be paired with the leader in Saturday's final group.
Fellow American Rickie Fowler, who first encountered McIlroy as an amateur at the 2007 Walker Cup in County Down, is a further two shots back after a 69, alongside compatriot Ryan Moore, Spain’s Sergio Garcia, Italy’s Francesco Molinari, and the South African duo of Charl Schwartzel and Louis Oosthuizen.
Tiger Woods almost paid the ultimate price for abandoning the tactics which previously brought him victory at Royal Liverpool.
Woods famously used his driver just once in 72 holes on his way to a third Open title in 2006 and was similarly circumspect in an opening 69 on Thursday.
However, wayward drives on the first two holes and an even worse one out of bounds on the 17th meant the 14-time major winner had to birdie the 18th - his only birdie of the day - just to be sure of making the halfway cut.
A round of 77 left Woods 14 shots adrift of halfway leader McIlroy.
Defending champion Phil Mickelson, who fell in love with links golf last year when he triumphed in Muirfield after 19 failed Open attempts, eagled the fifth hole on his way to a two-under 70 that kept him just about in touch on level par.
For the second day in a row the American drove out of bounds, although this time he still managed a par-five at the 10th with his replacement ball.
Shane Lowry and Graeme McDowell were best of the rest of the Irish contingent on one under, although they delivered very different rounds.
Graeme McDowell carded a 69, while Lowry laboured to a 75. A second consecutive round of 72 from Darren Clarke means he trails the pair by just a shot.
Amateur Paul Dunne improved on yesterday’s 75 as he registered a 73 but missed the cut by a single shot.
An abject 78 from Padraig Harrington also saw him miss the cut, while Michael Hoey was forced to withdraw after just seven holes of his second round. The 35-year-old was six over when he pulled out with a foot problem. The Northern Irishman does not yet know whether he will be fit enough to defend his Russian Open title next week.