Oakleys Rory McIlroy opened a six-shot lead over title rival Luke Donald after day one of the Dubai World Championship.
McIlroy must win the tournament and hope Englishman Donald finishes outside the top nine to end the year top of the European rankings.
McIlroy carded a double bogey on the second hole but fired six birdies on the back nine to propel him to six under par, two behind leader Peter Hanson.
Donald hit a disastrous three bogeys in a row to finish on level par and is equal 26th.
McIlroy, having found the bushes on the second hole, found himself three behind playing partner Donald and seven shots off the lead.
But Donald, who has the chance to become the first golfer to win both the European and American money titles, hit a poor drive left into the bushes on the 14th and had to chip out to safety before dropping a shot.
The world number one followed that bogey with another two bogeys on 15 and 16.
McIlroy, who won in Hong Kong last week, started his revival with a birdie on the 10th and finished with confidence, carding five birdies in his last six holes.
The 22-year-old said, who has been suffering from a virus said: "It's sort of taken the pressure off. I'm not 100% and there's nothing I can do about it.
"I made three poor mistakes on the front nine but stayed patient and the back nine was pretty much flawless".
"I certainly don't feel invincible, but I feel every time I tee it up I have a good chance of shooting a good score".
"It was the perfect start for me and really sets me up for the next three days. I didn't expect Luke to play the way he did."
Donald said: "I hit a few loose shots. They came out of the blue a little bit, although there were a couple of times last week when I had that left shot and I've got to keep working on it.
"I felt very much in control and then I lost it, but this course can do that to you. There are a lot of hazards in the middle of fairways, so you aim for one side and if you miss it you can be in the bushes."
Swede Hanson shot eight under to equal Lee Westwood's course record, with Scotland's Paul Lawrie second on seven under, one ahead of McIlroy.
Adidas Golf's Sergio Garcia, chasing a third successive European Tour win, is fourth after a 67.
Former world number one Lee Westwood managed a one-over-par 73, which included a double bogey on the short 13th after he had to play his second shot left-handed from the side of a bunker.