DUBLIN, Ohio — Overnight leader Rory McIlroy experienced a stunning free-fall to plunge nine strokes behind leader Paul Casey after the second round at the Memorial Tournament here Friday. After snaring the first-round lead with an opening 63 at Muirfield Village Golf Club, McIlroy notched three consecutive double bogeys en route to a six-over-par 78. But he did not blame his dismal day on a sore left knee he tweaked during the first round, instead admitting that it was poor driving caused his high score. “I just kept missing fairways and making it tough for myself and obviously that little three-hole stretch didn't help,” the Northern Irishman told reporters on a day when Englishman Casey surged three shots clear of the field. “Take those three holes out and it wouldn't have been that bad a day but these little runs I'm getting on it just seems to get away from me.” McIlroy was referring to the bad habit he has fallen into recently of shooting poor second rounds. In his past three PGA Tour events, he shot 77 (Masters), 76 (Wells Fargo Championship) and 74 (Players Championship) on Friday. McIlroy arrived at Muirfield Village fresh off winning the European Tour's flagship BMW PGA Championship at Wentworth Sunday, just days after breaking up with his tennis-playing fiancee Caroline Wozniacki. The resurgent Casey, on the other hand, did almost everything right to card a six-under 66 for 12-under 132, while Masters champion Bubba Watson bogeyed the final two holes to end the day in second place on nine-under. He has now a three-shot lead going into the weekend. Casey was ranked as high as third in the world in 2009, before injuries and divorce conspired to drive him to the brink of despair. Casey has found his game and confidence again over the past year. He won the Irish Open on the European Tour last June and has been in solid form since. World No. 1 Adam Scott lamented a 70 that left him seven strokes off the pace. “I had plenty of good golf and didn't take advantage of all my chances,” he said. Johnson ties course record Jennifer Johnson equaled the course record with a nine-under 62 to take a one-shot lead after the first round of the LPGA Tour's ShopRite Classic in Galloway, US, Friday. The 22-year-old American has one win on the LPGA tour, capturing the Mobile Bay LPGA Classic in 2013. “I've been playing well the past few weeks, and so I felt pretty good about my game, and you know, if you just let it happen and just let a good round come together, normally it does,” Johnson said. Japan's Haru Nomura carded an eight-under 63 to sit alone in second place, while Christina Kim, of the United States, is in third at seven-under 64 at the Stockton Seaview Golf Club course. World No. 1 Park In-bee and Choi Na-yeon shot matching five-under 66s to share fourth. Park has been ranked No. 1 for 59 straight weeks, but has yet to win a tournament this year. She rolled in a 15-foot birdie putt at her opening hole to get her round off to a strong start. Stacy Lewis, Michelle Wie, Sandra Gal, Chella Choi, Sarah Kemp, Laura Diaz, Brittany Lincicome, Jennifer Kirby and Gerina Piller were tied for sixth at four-under 67. Johnson's round included 10 birdies and a bogey as she equalled the course record set previously by Kang Ji-min and Laura Davies nine years ago. Johnson birdied three of her first four holes and almost made it four straight but settled for a par on the second. She went on to post five consecutive birdies beginning at the ninth. — Agencies