Rory McIlroy (Getty Images)
Rory McIlroy enjoyed a welcome change of fortune in The Players Championship with a first round 66 at TPC Sawgrass.
The World Number Two has failed to make the cut in three previous appearances at the event, but made light of past struggles today with a faultless opening 18 holes.
At six under, he was three behind surprise clubhouse leader Roberto Castro, who carded an eagle and seven birdies to match the course record of 63 set by Fred Couples in 1992 and equalled by Greg Norman two years later.
"It was a lot of fun," Castro told Sky Sports 2. "First time around here I was pretty nervous on the 17th, but birdied 17 and 18 which got things rolling into the front nine.
"Something solid was what I was hoping for. I'm usually really good at getting myself way out of it and having to dig myself out of a hole."
Starting from the 10th, McIlroy birdied the par five 11th, 12th and 14th to stand three under par approaching the daunting finish to the back nine.
A pushed drive on the par five 16th meant the 24 year old was unable to reach the green in two, but after pitching to 20 feet he rolled in the birdie putt and then struck a superb tee shot to the island green on the famous par three 17th.
The two time Major Championship winner - without a win so far in 2013 after five victories around the world last year - converted the birdie putt from seven feet and added a par on the 18th to be out in 31.
McIlroy missed from 12 feet for another birdie on the first, but picked up a shot on the par five second after coming up short of the green but hitting an excellent pitch to two feet.
Another birdie opportunity went begging on the fourth, while McIlroy saved par on the eighth after splashing out of a greenside bunker to seven feet.
McIlroy told Sky Sports 2: "It's my best score around this course by a long way so I'm very happy. I kept my ball in play for the most part and didn't make any stupid mistakes.
"I made a couple of good par saves, but apart from that I was giving myself a lot of chances for birdie.
"If I can continue doing that over the next three days I should be there or thereabouts going into Sunday.
"I feel good with my game. I wasn't hitting the ball great on the range but once I got out onto the course I felt a lot more comfortable.
"I said yesterday you have to find the balance between being conservative but also aggressive as well.
"I adopted quite a conservative strategy off the tee this week because I feel my iron play has been so good.
"Even if I leave myself a bit further back I am still giving myself good chances for birdies."
With conditions almost perfect for the early starters, McIlroy's 66 was matched by former Masters Tournament champion Zach Johnson, while Steve Stricker, Casey Wittenberg and Hunter Mahan all finished five under.
With the wind strengthening, it looked highly unlikely that any of the afternoon starters would be able to catch Castro at the top of the leaderboard ... and so it proved.
World Number One Tiger Woods briefly joined McIlroy and Johnson in a tie for second, having benefited from four straight birdies starting at the ninth, but a closing bogey left him five under.
Fellow Americans Ryan Palmer and Webb Simpson also went round in 67, while Padraig Harrington, Henrik Stenson and Sergio Garcia were among those one further back.
Forty of the world's top 45 are in the 144-strong field chasing the first prize of just over £1million.