Roberto Castro's 63 leads Players

PONTE VEDRA BEACH, Fla. -- Roberto Castro shot a 9-under 63 on Thursday in his debut round at The Players Championship to match the Stadium Course record and take the first-round lead at TPC Sawgrass.

Castro's bogey-free round included seven birdies and an eagle at the par-5 second hole.

The 27-year-old former Georgia Tech star missed a 13-foot birdie putt on the par-5 ninth that would have broken the course record, which he now shares with World Golf Hall of Famers Fred Couples (third round, 1992) and Greg Norman (first round, 1994). Norman went on to win the tournament.

Castro holds a 3-shot lead over Rory McIlroy and Zach Johnson, who both shot 66 on Thursday. Tiger Woods was in a logjam at fourth place after an opening 67.

"I hit it close a lot," Castro said of his round, which began on the 10th hole. "I hit a couple of gimmes on the back, but really birdies on 17 and 18 got things going. I hit a 4-iron close on 18 to kick in almost. So from there, it was kind of off to the races."

Castro's best finish this season is a tie for 21st at the Tampa Bay Championship in March. In his second year on the PGA Tour after earning his card through the 2011 qualifying school, the Houston native said his performance Thursday was a good sign that his game is finally coming into form.

"The last two weeks I've hit the ball really nicely," he said. "I have not gotten the scores out of it. But a lot of greens in regulation, a lot of fairways hit, a lot of quality shots, so I thought that would be a good thing coming into this week where you have to hit it nice and solid, nice and straight."

McIlroy's 66 marked the first time that he has broken par at the Stadium Course in seven career rounds in the tournament. In three previous appearances at the PGA Tour's marquee event, he missed the cut.

Starting his round on No. 10, the 24-year-old Northern Irishman had five birdies on that side, including one at the par-3 17th, where he landed a short iron to five feet on the island green and made the putt.

Through 12 holes, McIlroy shared an identical score with Steve Stricker, who had a 67. After a birdie at the second hole, McIlroy had pars on his remaining seven holes.

"I played well," he said. "I gave myself plenty of chances. It could have been better, but I'm not complaining. This is my first under-par round here. I'll take anything I can get."

Vijay Singh, playing one day after he sued the PGA Tour for its handling of his doping case, was largely ignored while playing in the group behind Woods. One fan wore felt deer antlers in the bleachers behind the first tee -- Singh's case involved taking deer-antler spray -- but only a dozen or so people followed the 50-year-old Fijian on the back nine and it was a quiet day.

At one point, Singh let out a hearty laugh walking off the tee with Robert Garrigus and J.J. Henry. His golf wasn't the subject of the laughter. Singh hit into the water on the last hole and made bogey for a 74, leaving him in danger of missing the cut.

So ended a first round filled with plenty of action -- a record-tying score by a player hardly anyone knows, McIlroy breaking par for the first time at Sawgrass, 17 balls in the water around the island-green 17th and 33 rounds in the 60s.

Padraig Harrington followed an eagle with a double-bogey. Michael Thompson made a hole-in-one.

Woods, Webb Simpson and Ryan Palmer at 67 had the lowest rounds among those who played late, and they now turn around and get the morning conditions -- hopeful they'll be the same -- on Friday.

The Stadium Course rarely has looked so vulnerable with barely a trace of wind and some pins in bowls that allowed for good looks at birdie. Half the 72 players in the morning broke par.

But the punishment is never far away, as Scott Stallings discovered. He opened with five straight birdies to get everyone's attention, but after going out in 31, Stallings gave most of it back with a bogey, a double-bogey and a triple-bogey on the 16th when he hit two balls into the water. He shot 40 on the back for a 71.

"It just goes to show about the golf course and really how volatile it is," Stallings said.

Information from The Associated Press was used in this report.