Rory McIlroy roars ahead in the first round of the Memorial Tournament, topping the leaderboard by three shots. Magical Rory McIlroy / Getty Images Rampant Rory carded a first round -9 under par 63 at Muirfield Village, taking a three shot lead into the second round of the Jack Nicklaus hosted event. That score included a double bogey as well, which denied Rory a chance of setting a new course record. The flight over from England, fresh from his win at Wentworth, did not bother him one little bit. Even a tweak in his left knee on the 7th hole did not deter him either; "Monday seemed like a long day and it just sort of felt like when I got here it was just a different tour. You're getting ready for the U.S. Open. It's a big tournament, the Memorial in itself. "And I prepared well. I came here early Tuesday morning, practiced, did a good session on the range yesterday after the pro-am in the afternoon, so I've been putting a lot of work in, and it seems to be paying off." "I wear spikes, so sometimes your foot can get stuck in the ground and you can torque your knee a little too much. I think that's what I did, I tweaked it. The inside of it is sore, it's a little swollen. Go see the physio and get some treatment and get ice on it, and hopefully it will be OK for tomorrow." Rory needed only 22 putts during this first round and said that this sort of form had been in the pipeline for sometime; "This has been coming, it's been coming. My performances have been really good, been shooting really good scores. There's just been runs of holes in tournaments where I haven't played so well and I've shot it 4 or 5 over in the space of nine holes, and that's really just derailed my tournament." "Last week I just didn't do that. And that's down to nothing more than hitting good golf shots and hitting good putts and limiting my mistakes whenever I get in trouble on the golf course." There are three players tied in second place at -6 under par after completing their first rounds of 66, which is a good score around this course. Paul Casey, Chris Kirk and Bubba Watson are the guys trying to chase down Rory. Phil Mickelson was putting together a decent first round until the last three holes, dropping from -5 under par to even, in the blink of an eye. He does not like the 16th since Jack redesigned it in 2010, he made bogey there and then recorded double bogey from the middle of the fairway at the 17th. Another mess at the 18th hole where he three-putted for another double bogey. Phil spoke about that 16th hole; "It's a feast or famine hole for me, it doesn't set up well for a left-handed shot dispersion. It has to be a perfectly struck shot. And I just go in the water there most of the time, because I don't want to pull it way to the right. I was playing well, but the last three holes just threw away a good round."