Published Thursday, 01 March 2012
Rory McIlroy hits his tee shot on the 17th hole during the first round (© Getty)
The 22-year-old Holywood man, who needs to win to topple Luke Donald as world number one this weekend, set the early clubhouse lead.
Justin Rose joined him after hitting back from an early double bogey with an eagle and four birdies.
Meanwhile, Ian Poulter was due to play with Tiger Woods and Lee Westwood, but said on Twitter: "Sorry guys - never been so disappointed in pulling out of a tournament. Never felt so rough."
On Wednesday night he tweeted: "Heading straight to bed, 101.2 temperature, freezing then sweating. I hope I can sweat it out overnight or it could be home for me." He even took a picture of the thermometer.
His place went to Argentina's Miguel Angel Carballo, a PGA Tour rookie ranked 299th in the world.
McIlroy grabbed his first birdie after a 165-yard approach to five feet on the 14th - his fifth - and added a 12-foot putt on the short 17th before two-putting the 556-yard 18th to turn in 32.
Further birdies came on the second and seventh, but he was more than 50 feet from the flag on the next green and three-putted to drop his only stroke.
Rose's double bogey came after a wild drive down the second, but he eagled the next from nine feet, then had a hat-trick of birdies from the fifth and picked up another second at the 16th.