Delasin, who was four shots behind Hanna at sixth at the start of the round, birdied two of the last six holes to card a 35-35 round at the Randolf Park Golf Course as the Fil-Am Rookie of the Year tied Deb Richard (70) at 205 heading into the final 18 holes of the $750,000 championship.
That was five shots behind Sorenstam, whose bogey-free round of 67 and a 200 gave her a two-stroke lead over Korean ace Se Ri Pak, who matched Sorenstams five-under par to emerge the challenger at 202.
Hanna had a 72 and slid to third place at 203. Jennifer Rosales also carded a 70 on a birdie-birdie windup as she climbed four rungs from 19th place to remain in contention for another top 10 finish after placing third in the LPGA Office Depot last month. She had a 208.