Rory McIlroy squandered a two-shot lead with eight holes to play as China's Li Haotong claimed the biggest win of his career in the Omega Dubai Desert Classic.
McIlroy overturned a one-shot overnight deficit with the aid of three birdies in the first 10 holes at Emirates Golf Club, but bogeyed the 11th and 16th as well as three-putting the 15th for par.
And although the four-time major winner birdied the final two holes, Li did likewise under enormous pressure to complete a closing 69 and win by a single shot.
Li's 23-under-par total is a tournament record and gives the 22-year-old a second European Tour title, as well making him the first male Chinese player to break into the world's top 50.
McIlroy has now finished third and second in his two starts since calling an early end to an injury-plagued and winless 2017 campaign, but will be disappointed at failing to convert a two-shot lead at halfway.
The 28-year-old's closing 69 left him on 22 under par, two shots ahead of England's Tyrrell Hatton, who saved par on the 18th in a closing 66 despite finding the water with his approach.