He is looking to become only the second Swede in 76 years to win the European title. He is five shots ahead of his Race to Dubai rivals.
Stenson had eight birdies in a bogey-free round to move to 12-under 132 halfway through this event at Jumeirah Estates.
Spain's Alejandro Canizares (67) was at 133. At 136 were France's Victor Dubuisson (66), last week's Turkish Open champion, and Australia's Marcus Fraser (69).
Justin Rose, second in the Race to Dubai, and Ian Poulter, who is fourth, lost ground to Stenson. They were in a group at 137.
