DUBLIN, Ohio (AP) — Charl Schwartzel changed his putting grip and squeezed about as much as he could have out of his round.
Several hours later, Tiger Woods left a lot of shots out on the rolling greens of Muirfield Village and 14-year-old Chinese amateur Guan Tianlang added to his impressive list of American adventures.
Schwartzel, the former Masters champion who has all but dropped out of sight since, strung together four birdies on each side in a 7-under 65 to take a one-shot lead after Thursday's opening round of the Memorial Tournament.
The South African, who won at Augusta in 2011 but hasn't won or placed second on the PGA Tour since, tinkered with his putting stroke after missing a short putt and settling for bogey on his fourth hole.
Magically, he started making everything he looked at.
"I've been hitting the ball good," he said. "I started off the same thing this morning, flushed it for the first four holes and two-putted for birdie on 11. Then I hit it to 4 feet on 13, it looked like I was going to go to 2 under, and I made bogey. So I went to the next hole, changed the grip and they started pouring in."
He rolled in birdie putts of 10, 6, 24 and 7 feet on the next four holes. He later made birdies from 14, 11, 11 and 9 feet on his second nine.
"You get those rounds where you really strike it well and you're making lots of birdies and you walk off with your 8 or 9 under," he said. "Today was one of those where I really did flush it."
Well, he did at least until he got to the par-3 8th hole, his 17th of the day. His 8-iron ended up in the bunker which almost surrounds the green, he blasted out long, chipped down to the hole and missed a 10-footer for bogey. The double dropped him off the lead, but he made up for that on his last hole by hitting just past the pin on the par-4 and then coaxing in the putt.
"The birdie on the last definitely will make my evening a lot better," he said.
Scott Piercy, dialing back with a 3 wood and avoiding pulling out the big lumber, was a shot back with a 66. Fred Couples, who will captain the American side in the Presidents Cup also at Muirfield in October, shot a 70. Playing in the same group with Couples, Woods had to settle for a 71. Guan, the eighth-grader who became the youngest player ever to make a cut in a major championship at the Masters, shot a 72.
Woods was imprecise all day, particularly out of the grabby, thick rough which lines the ample fairways at the tournament founded and hosted by Jack Nicklaus.
"All in all, it was a pretty high score," said the defending champ and five-time winner at the Memorial. He had three bogeys coming home, including on the closing hole after spinning his approach back off the front.
"I didn't score very well compared to how I hit it," said Woods, who hit 11 of 14 fairways and 13 of 18 greens in regulation. "I hit it pretty good. I just didn't make anything today. Hopefully tomorrow I'll make a few more putts."
Couples outshone his partners (former PGA Championship winner Keegan Bradley also had a 71) despite making double at No. 8 and a bogey on the next hole.
"We don't play it like this all the time," he said of the course, famous for its frequent thunderstorms as the first Northern course to host a PGA Tour event each year. "It played really, really fast."
Couples visited the White House on Wednesday as part of a publicity tour for the Presidents Cup.
Guan, showing aplomb beyond his years, had three birdies against three bogeys, the last on the closing hole when he followed Woods' lead and spun his approach off the false front.
Instead of getting angry, he was determined to do even better.
"Probably a couple under will be great," he said of his second-round goal. "I'm planning to make the cut if I hit a couple under."
The long-hitting Piercy's 66 featured him showing great restraint by not reaching for his driver.
"Everybody is like, 'Man, you must love Memorial. You play great there,'" he said. "I'm, like, 'I play terrible here.' I had to tell myself for a couple of days, 'You're just going to hit a 3-wood and see where it goes, because the driver hadn't been working.'"
With a missed cut and no finish in the top 40 in his first three trips to Muirfield, so far the new approach has paid big dividends.
Josh Teater, Russell Henley, Kyle Stanley and Charlie Wi were at 67, Bill Haas and Matt Kuchar another shot back, and Matt Jones, Michael Thompson, Robert Karlsson and Chris Stroud at 69.
Rory McIlroy, hoping to use the Memorial as a springboard to the U.S. Open in two weeks at Merion, instead fell flat. He lapsed to a 78 and was already 13 shots off the pace.
"Coming off the (final few events) last year, I was playing very well and winning a few times, including a major championship," the world No. 2 said. "Of course you want to come into this year and try and do the same sort of things. I just hasn't really happened."
Follow Rusty Miller on Twitter: http://www.twitter.com/RustyMillerAP