Several second round blow-outs this season, the most recent at the Scottish Open, meant all eyes were on the 25-year-old Northern Irishman to see if he could capitalise on his one-stroke overnight lead rather than shoot himself in the foot.
Apart from a jittery bogey on the first, his only dropped shot so far, he was immaculate, racking up seven birdies for a second successive round of 66 for a 12-under total of 132.
Tiger Woods attracted huge galleries but a triple bogey at the 17th meant the 14-time major champion needed a birdie at the last to make the cut by his fingernails.
He duly obliged but barring an extraordinary turnaround in his form he will be making up the numbers at the weekend.
Less celebrated American Dustin Johnson will lead the chase of the run-away McIlroy after a tournament best seven-under 65 fired him into contention for his first major.
Fellow Americans Rickie Fowler and Ryan Moore were in a group of six players on six under, which also included Italy's Francesco Molinari, Spain's Sergio Garcia, 2011 US Masters champion Charl Schwartzel and 2010 British Open winner Louis Oosthuizen.
After a relatively calm opening day, warm, gusting winds of around 20mph meant birdies were at a premium for the early starters with South African George Coetzee the only player to make a move with a 69 that gave him the clubhouse lead.
The birdies and eagles flowed later, however, as the wind lost its strength and the leaders, most of whom got the best of Thursday's weather, began to make hay in the sunshine.
Even the local wildlife came out to play as McIlroy's charge was briefly halted by a curious pheasant that wandered across the eighth green before he drained another long putt.
McIlroy, who won the US Open by eight strokes in 2011 having also reached double figures under par by the weekend, was not about to let his so-called Friday demons ruin a gilt-edged chance to seize control of the Open.
FRIDAY NERVES
Laser-straight off the tees, delicate with his wedge and hot with the putter, McIlroy shrugged off his scruffy start to birdie three of the four par-fives on the coastal links and notch twos at the par-three sixth and 15th.
By the time he reached the par-four 17th, where Woods racked up a horrid seven after going out of bounds, there was no stopping him as he launched a drive of nearly 400 yards on his way to yet another birdie.
McIlroy walked off the 18th green with the stride of a man in complete control and afterwards he told reporters that far from any Friday nerves, he had felt an "inner-peace."
"My second rounds this year have been terrible," McIlroy told reporters. "And there isn't really any explanation.
"But hopefully I put it to bed today."
Thunderstorms predicted for Saturday could complicate matters, but McIlroy said he was right where he wanted to be.
"I haven't been in this position in The Open Championship," he said. "But I'm just really looking forward to the weekend and hopefully continuing the strong play that you've seen so far."
The big-hitting Johnson will be a threat though.
He fired seven birdies in a blemish-free round on Friday and his duel with McIlroy on Saturday promises to be fascinating.
Should McIlroy fail to close the deal this weekend, Garcia would be an equally popular winner.
TERRIBLE START
The Spaniard gave the galleries his full repertoire on Friday in a round of 70, the best coming on the second where he holed his approach from 160 yards for an eagle.
Three bogeys took the shine off his day but Garcia, yet to win a major, was smiling broadly after a birdie on 18.
For the second day in succession Woods made a terrible start - only this time it was worse.
A double-bogey six on the first, where he lashed his tee shot into deep rough, set the tone and he dropped another shot on the second before grinding out 14 consecutive pars.
At level-par the 38-year-old was still heading comfortably into the weekend but calamity struck on the 17th where, after going out of bounds he ran up a seven.
Lesser players would have cracked completely but the American showed tremendous focus to claim his first birdie of the day on the 18th to put him on the +2 cut line.
"I got off to a terrible start again. I had some opportunities to make a few birdies along the way to get back to even par for the day and I just never did," he said.
"I'm pretty far back. Luckily I've got two rounds to go. And hopefully I can do something like Paul (Lawrie) did in '99."
Lawrie famously came back from 10 shots back to win the Open that year but with Woods clearly rusty after returning from back surgery in March, a first major since 2008 looks beyond him.
Several big names trying to kick start their challenges early on Friday suffered frustration.
World number one Adam Scott, who began the day two shots off the lead, dropped shots at the second and third holes, both par fours into the wind, although he did earn one back at the fifth.
The Australian ended the day with a couple of birdies to sit three under going into the weekend. Defending champion Phil Mickelson eagled the fifth hole on his way to a two-under 70 that left him a distant 12 shots off the lead.
Masters champion Bubba Watson missed the cut on four over - fate that also befell former world No.1 Lee Westwood, Europe's Ryder Cup hero Ian Poulter and Justin Leonard.
