Defending champion Branden Grace held a slender lead heading into the closing stages of the Commercial Bank Qatar Masters as Paul Lawrie's hopes of a third title suffered a major blow.
Lawrie took a two-shot lead into the final round and maintained that cushion by matching Grace's birdie on the first, but bogeyed the second after his wayward drive ended up on the edge of a small bush.
Both Grace and Lawrie dropped shots on the fifth after failing to get up and down from over the green in the windy conditions, allowing Denmark's Thorbjorn Olesen to join Lawrie in the lead after his birdie on the previous hole.
Grace holed from 25 feet on the sixth to make it a three-way tie and after Olesen dropped back with a bogey on the eighth, Lawrie also slipped out of the lead on the ninth.
The 47-year-old hooked his drive into the desert scrub and found the water on the other side of the fairway with his attempted recovery, eventually carding a double-bogey seven.
That left Grace in the lead on 12 under, with Olesen and England's Lee Slattery on 11 under and Lawrie and Andrew Johnston a shot further back.