Overnight leader Richard Green struggled in the hot conditions on Saturday. He shot a 1-over 73, but it still within striking distance of first. Green is tied for second place with Niclas Fasth, who shot a 69 in the second round, at 8-under-par 208.
Only six players broke 70 on Saturday and aside from Stenson's 66, they were all 69s. One of those belonged to world No. 3 Ernie Els. He is tied for 10th place at minus-5 and still has a chance to win in back-to-back weeks.
'That's the best I've played all week and felt I could have shot better,' admitted Els, who won last week's Dubai Desert Classic. 'I have an outside chance and we'll see what happens if there is a bit more breeze to make it difficult. I burned a lot of edges today but I kept my hope alive.'
Stenson started slowly with a birdie at the fourth, but tallied five pars to complete his front nine. He ran off three consecutive birdies from the 10th to reach 8-under par and match Green atop the leaderboard.
Stenson birdied the 16th and 17th holes to go two clear of Green and Fasth, who charged up the leaderboard thanks to four birdies in a five-hole span on his back nine.
Green bogeyed 14, but reclaimed the lost stroke at 16. Green trails Stenson by two heading into Sunday and the Swede is cautious about his chances.
'It's still a very open tournament and I think it's going to be a tight race with Niclas and Richard right up there,' said Stenson. 'Ernie's still there as well and he might give it a shot tomorrow. He's always dangerous when he gets going.'
Stenson is a two-time winner on tour with wins at the 2001 Benson & Hedges International Open and The Heritage last year. Stenson already has two top-10 finishes in the 2005 season - a tie for sixth at the Heineken Classic and a third at the Malaysian Open.
'It's certainly put me in a good position and a lot can happen,' said Stenson, who added that forecasts for heavier winds on Sunday might make the tournament more open. 'I've got a good chance now, I think.'
Green made two bogeys on Saturday, one at the par-4 sixth and the other at 14. He reclaimed the lost stroke with his third birdie in as many rounds at 16, but the Australian seemed fatigued after the round.
'I used up a lot of mental energy trying to save par and had nothing in the tank at the end,' admitted Green, who lost in the first round to eventual winner David Toms at the WGC-Accenture Match Play Championship. 'I am going to stock up on energy goods tonight and go out there and try to get on a roll tomorrow. I lacked momentum today and clearly Henrik had that going for him.'
Fasth, a Swede who played on the Ryder Cup team in 2002, was 1 over on his round through 11 holes, but closed with four birdies in his final seven holes for his 69.
'I'm just pleased to be a couple back,' admitted Fasth, who won last month's New Zealand Open. 'No one has really taken charge except for Henrik so although I didn't get a low scoring round, I'm still in there.'
Pierre Fulke shot a 1-over 73 and is tied for fourth with Barry Lane, who carded a 69 on Saturday. The duo is knotted at 7-under-par 209.
Arjun Atwal (71), Marcus Fraser (70), Gregory Havret (72) and Robert Karlsson (74) are tied for sixth place at 6-under-par 210. Els was joined in 10th by Raphael Jacquelin (73), James Kingston (69) and Steve Webster (69).