Luke Donald's prospects of becoming the first man to win the US and European money lists in one year improved on day two of the Dubai World Championship.
A top-nine finish would guarantee it, and the world number one was tied for 12th after a 68 left him at four under.
Rory McIlroy would claim the money list with victory if Donald were to finish outside the top nine but he dropped two late shots to fall five off the lead.
Alvaro Quiros is four ahead at 12 under after an eagle at the 18th in his 64.
Beginning the second round two shots behind at six under, McIlroy picked up three birdies in his first 11 holes.
But he misjudged a chip, which lodged in the greenside mound at the par three 17th and another shot went at the last when he drove into the water.
Moments earlier, Quiros had fared far better on the 620-yard par-five, with a drive and a three-wood to 12 feet for an eagle three.
Donald, who had three successive bogeys in an uncharacteristically wayward opening round of 72, finished with three consecutive birdies on Friday.
McIlroy has been suffering from a virus for the past few weeks and has now been told he might have been battling with dengue fever, transmitted by a mosquito bite and fatal in less than 1% of cases.
"It could have been a number of things and I'm going to see a doctor again before deciding whether to go to Thailand next week," the 22-year-old said.
"To be honest, I'm ready for the season to be done and looking forward to putting the clubs away."
Donald admitted he had still had problems in round two and said: "I was frustrated out there. I tried to stay patient, but it's tough. I want to finish off what I came here to do and those last three holes brought a smile to my face.
"There's certainly a lot of pressure. I'm still making a few mistakes - maybe because of what's at stake. When there's a lot on the line you feel more nervous, but sometimes it's a good thing."