Kim Williams holed out from a bunker for a birdie at 16 en route to a 6-under 66. She is alone in second place at minus-12, while defending champion Cristie Kerr and Catriona Matthew each shot rounds of 5-under 67 and are knotted in third place at 11-under-par 205.
Hurst collected four birdies in her first six holes, but dropped a shot at No. 7, a hole she has now bogeyed twice in as many days. She parred her last two holes on her front nine to make the turn at 3-under 33.
On the second nine, Hurst flew out of the gate with three straight birdies from the 10th. She reached 15 under par for the championship with a 25-foot birdie putt at the 15th. Hurst holed a clutch 7-footer for par at the next hole after finding a bunker, then two-putted for pars from 20 feet at her final two holes.
This marks the fourth time Hurst took the third-round lead of a tournament and she is 2-1 in her previous experiences. If she visits the winner's circle on Sunday, it will be for the fourth time on the LPGA Tour and her first since the 2000 Electrolux USA Championship.
To get to the trophy presentation, Hurst will have to erase some bad memories from one week ago. She was tied for the lead on the final tee Sunday at the Wendy's Championship for Children with Kerr, but hit a terrible drive and ended up with a double bogey. Hurst finished two shots behind Kerr.
Hee-Won Han (70), Natalie Gulbis (70), Maria Hjorth (71) and first-round leader Heather Bowie (71) are tied for fifth place at minus-9. Aree Song (66), Diana D'Alessio (66) and Heather Daly-Donofrio (70) share ninth at 8-under-par 208.
Second-round co-leaders Tina Barrett and Sherri Turner struggled on Saturday. Barrett posted a 2-over-par 74 and is part of a group tied for 12th at minus-7, while Turner managed a 4-over 76 and is tied for 31st at 5-under-par 211.