DUBLIN (AP) -- If this keeps up, Rory McIlroy's golf game may just push his personal life out of the headlines.
After winning on the European Tour last week, McIlroy overcame a tweaked knee and a double-bogey to shoot a record 9-under 63 for a three-shot lead after Thursday's opening round of the Memorial Tournament.
"I was expecting this to happen. I've been playing well. I've been posting good numbers, good rounds. And I knew my game was close," he said after breaking the first-round scoring record at Jack Nicklaus' signature tournament. "Honestly, I don't think it's got anything to do with what's happening off the golf course. It's just I've been trending in the right direction, and it's starting to all come together."
McIlroy, of course, announced last week the end of his engagement to tennis star Caroline Wozniacki. The two had shared a high-profile relationship on social media. When their wedding plans fell apart and they separated, it was big news around the world.
With so much drama in his life lately, it's as if the 25-year-old from Northern Ireland has eliminated all the suspense in his game. Following a win at Wentworth, he absolutely torched Muirfield Village. He had eagles at 11th and 15th holes and tossed in seven birdies, breaking the first-round mark held by three players -- despite a double-bogey at the 14th.
"I don't think it's anything more than just being confident with my game," he said.
What's more, McIlroy did it despite injuring his left knee on his second shot at the par-5 seventh hole. He hobbled for the next few holes, continually flexing it in between shots.
"I wear spikes, so sometimes your foot can get stuck in the ground and you can torque your knee a little too much," he said. "The inside of it is sore, a little swollen. I'll go (to the fitness trailer) and get some treatment and get ice on it and hopefully it'll be OK for tomorrow."
He'll have to be healthy to keep ahead of a stellar leaderboard.
Masters champ Bubba Watson led the trio in second. Paul Casey, playing at Muirfield Village for the first time since 2009, also had a 66, along with Chris Kirk.
Watson said he's learning to juggle fame, his job and his home life.
Keegan Bradley, playing with a regulation-sized putter instead of an anchored, longer model as he usually does, was at 67 along with Michael Thompson and J.B. Holmes. Justin Leonard -- recording his best round at the Memorial in 12 years -- shot a 68, as did Hunter Mahan and Ryan Moore.
World No. 1 Adam Scott was at 69 and Phil Mickelson, trying to turn things around at a tournament where he has seldom contended, closed bogey-double-double for a 72.