Sorenstam, who is stepping away from the game after this event, completed 36 holes at 8-under-par 136. That was good for a one-stroke lead.
Nikki Garrett also fired a 66 and is one stroke back at minus-7.
First-round leader Johanna Head managed an even-par 72 Friday that dropped her into a share of third place at 6-under-par 138. She was joined there by Veronica Zorzi (69) and Maria Verchenova (66).
Sorenstam parred her first two holes, then made eagle on the par-5 third to jump to 4 under. After two more pars, she carded three birdies in the next four holes to climb to 7 under.
The Swede parred the first three holes of the back nine at Emirates Golf Club. Sorenstam posted her final birdie at the par-5 13th, then parred the final five holes to close out a bogey-free round.
'My goal was to clean up the round that I had yesterday with no bogeys and I was able to do that, so I'm very, very happy,' Sorenstam stated. 'I wish I could have done a little better. I know I had a lot of chances and edges really. I hit the pin on the 11th hole, but I hit some good shots and I hit some good putts that just didn't go in.'
Garrett played the back nine first and birdied the 11th and 18th. Around the turn, she birdied two, four, six and eight to move to 7 under.
Laura Davies, Anja Monke and Iben Tinning share sixth place at 5-under-par 139. Amy Yang and Carin Koch are among eight players tied for ninth at minus-4.