DUBLIN, Ohio — Paul Casey expected to be chasing someone Friday in the Memorial, figuring it would be Rory McIlroy.
After two holes, Casey had the lead to himself at Muirfield Village, and that was only the start of another big day. He took advantage of the par 5s for another 6-under 66, giving him a three-shot lead over Masters champion Bubba Watson going into the weekend.
McIlroy, whose 63 was the lowest first round in the 39-year history of the tournament, was barely in the picture. He was 15 shots worse with 78, courtesy of three straight double bogeys and his fourth straight PGA Tour event with a nine-hole score of 40 or higher. McIlroy went from a three-shot lead to nine behind.
"To be honest, I thought I was going to be playing a round to try and maybe catch a couple of guys," Casey said. "I woke up checking the scores to see what Rory was going to be. That's really what I was going to be doing — see how many under I was going to have to try to shoot to chase. Obviously, that didn't happen."
Casey, taking another step on a long road back from injuries that nearly derailed his career, was at 12-under 132.
Chris Kirk (70) was four shots behind. Hideki Matsuyama (67) and Martin Flores (68) were five back.
Adam Scott, who won Colonial last week in his debut at No. 1 in the world, shot 70 and was 5-under 139. Phil Mickelson was happy to get in two more rounds. He shot 70, though he was 10 shots back.
McIlroy shot 43 on the back nine — he started the round at No. 10 — making this the fourth consecutive PGA Tour event where he shot at least 40 over nine holes. All of them have been in the second round.
McIlroy twice hit the trees on the 13th hole and made double bogey. He hit into the water on the 14th for double bogey. And then he double-hit a wedge on the 15th to make it three straight double bogeys.
"These little runs I'm getting on where it gets away from me, I was able to avoid that last week," he said. "Not so much this week. Even though I had such a bad day, I'm still in with a chance depending on what the guys do this afternoon. So going into the weekend, not exactly where I want to be. But it could be worse."
LPGA: Jennifer Johnson matched the course record with 9-under 62 to take the first-round lead in the ShopRite Classic in Galloway Township, N.J. The 22-year-old had 10 birdies — five straight on Nos. 9-13 — and a bogey on the Bay Course at Stockton Seaview Hotel and Golf Club. Haru Nomura was in second place at 63, and Christina Kim opened with 64. The only others to shoot 62 at Seaview were Laura Davies and Jimin Kang in 2005.
Champions: Mark Calcavecchia and Wes Short shot 6-under 66 to share the first-round lead in the Principal Charity Classic in Des Moines, Iowa. Calcavecchia, 53, a former Florida Gator standout, had three straight birdies on the back nine for his best start of the season. Bobby Clampett, Peter Senior and Shane Lowery were a stroke back.