The real Rory McIlroy returned to what he does, finding fairways with bombed drives and hitting greens and sinking putts. The impostor of a week ago had vanished.With a pep back in his step compared to the slumped shoulders which accompanied much of his movements in a dreadful outing in the St Jude Championship in Memphis where he finished in 66th position, McIlroy returned to the softened fairways of Bellerive Country Club in St Louis and posted an opening round of 64. His six-under score in the BMW Championship earned him a share of the clubhouse lead.His pride was hurt after his display in Memphis, the remedial work carried out at home in Florida with coach Michael Bannon. The rustiness of a week ago was replaced by a sharpness and a fresh intent, his bogey-free round rounded off with a birdie-birdie finish that saw him join Gary Woodland and Wyndham Clark atop the leaderboard at that juncture.In demonstrating the fickleness of golf and all of its craziness, world number one Scottie Scheffler – a runaway winner in Memphis to cement his position atop the FedEx Cup standings – struggled in the BMW with a hat-trick of bogeys from the third and an outward nine of 38 that had him holding up the field.McIlroy’s bogey-free round of six birdies started on the fourth with a right-to-left breaking 10-footer and was followed by a 12-footer on the eighth before a homeward run that brought birdies on the 13th, 15th, 17th and 18th, from 10 feet to close. He barely put a foot wrong.The difference from a week ago? “I went home and I worked on a few things and at least got myself back in a frame of mind where like I felt like I’m at least back on the right path of what I’m doing with my game and with my swing. “It’s certainly a work in progress. Days like this are encouraging, obviously. There’s still a lot of work to be done. But for, you know, first round with what I’m trying to do, middle rehearsal on the takeaway, all that sort of stuff, it went as well as it could have today, for sure.”Certainly, the weather of recent days – which contributed to a softer course set-up – worked in McIlroy’s favour too.He knew it. “The golf course, it’s my style of golf course. I do well on these golf courses. They’re big, they’re long. You can get away with missing some tee shots at times, definitely a course that sets up better for me than the one we played last week,” admitted McIlroy, who, regardless of whether he wins the BMW or not, will head into next week’s Tour Championship in Atlanta for a 30-player tournament that has a level playing field.