After a headache brought on by pollution on day one, McIlroy remained composed in posting a seven-under-par 65 to move to 12-under par and trail Ryder Cup-winning colleague Peter Hanson by two strokes.
Hanson signed for a career-best equal low of 64 to move to 14 under par on the Lake Malaren course.
McIlroy, like all in the 78-player field, found himself having to deal not only with the on-course distraction of the ‘quack, quack’ mobile phone ring tones but the more noticeable off-course sounds. They included pile-driving machinery noise from nearby construction sites, police sirens, the sounds of primary school teachers shouting instructions to their pupils ahead of gymnastic exercises, random outbursts of music and, bizarrely, some half-a-dozen fireworks displays for what reason no one could explain.
McIlroy took it all in his stride to record his fifth 65 of the year as he strives also to capture a fifth success this season.
“You are always going to have distractions out there, whether it is people with their cameras or movement in the crowd or fireworks from I don’t know where they were coming from,” said McIlroy.
“But then once you’re over a shot, you’re sort of in your own little bubble and your zone an you don’t really notice those sorts of things.”
Shane Lowry produced his best score in 18 months, an eight-under-par 64, to lie in a tie for fourth place on eight under, a shot behind third-placed Swede Robert Karlsson.
Michel Hoey carded a 70 to trail Hanson by seven while Graeme McDowell (71) is next best at four under par with Paul McGinley (75) and Darren Clarke (76) at five over par in the no-cut event.