Alviro Quiros retained control of the Dubai World Championship with a two-under-par 70 on Saturday, as Rory McIlroy's challenge faltered.
Quiros had roared into the lead with an eight-under second round of 64 on Friday.
The Spaniard was unable to match that blistering performance on Saturday, but he remains alone at the top of the leaderboard, 14-under overall with one round remaining at the Jumeirah Golf Estates.
The tournament was billed as a showdown between world number one Luke Donald and US Open champion Rory McIlroy.
Englishman Donald is aiming to become the first man to top both the US PGA and European Tour money lists for earnings in a single season.
World number two McIlroy must win in the United Arab Emirates if he is to prevent Donald from achieving the feat.
But the Northern Irishman appears hard pressed to challenge on Sunday after he carded a second successive one-under 71.
McIlroy's indifferent display leaves him tied for eighth, six shots off the pace.
And Donald carded his lowest round yet of the first three days, with a six-under 66 firing him to outright fourth at 10 under.
Scotland's Paul Lawrie and South African Louis Oosthuizen matched Donald's 66, and sit second and third respectively behind Quiros.
The defending champion, Sweden's Roberto Karlsson, produced his best display of the tournament with a four-under 68.
But following disappointing rounds of 72 and 73, it was only enough to earn him a share of 22nd, 11 shots back from Quiros and apparently out of contention to retain his title.