Jeong Jang, one of the four second-round leaders, posted a 2-under 70 to end in a tie for second at minus-9. She was joined there by Kim Saiki, who carded a 67 in the final round. Juli Inkster took fourth at minus-8.
Jee Young Lee and Gloria Park shared fifth at 6-under-par 210.
Hurst came flying out of the gate with a birdie on the first when she stuck her approach 3 feet from the hole. She then birdied three and four to get to minus-9 . Hurst two-putted for birdie on the par-5 fifth, her third straight birdie in the round and third in three days on that hole.
The 37-year-old stumbled to a bogey on the sixth when she could not get up and down from a bunker, but rebounded with a two-putt birdie at the par-5 seventh. Hurst parred three in a row around the turn.
Hurst got to 11 under for the first time with a birdie on the 11th. She slipped to a bogey on the next, but recovered that stroke with a 6-foot birdie putt on 15. The five-time winner on the LPGA Tour tripped to a three-putt bogey on 17, but a par at the last secured the win for Hurst.
'I played pretty well. I started off making birdie on three of the first five holes, and just kept going from there,' said Hurst, who picked up $210,000 for the win. 'I played steady after that. I had a couple of bogeys, but overall I hit the ball very well and just kept the ball in play and played a steady round.'
Jang, the 2005 Women's British Open champion, birdied No. 3 to get to eight- under. She later two-putted for birdie on the seventh for the third day in a row.
Around the turn, Jang birdied the 11th, but gave that stroke right back with a bogey on 12. She had a chance to force a playoff with Hurst, but could only par the final six holes.
'I'm just disappointed I made bogey on 12,' Jang said. 'It was kind of a birdie hole to everybody else. After that, I thought really hard about first place, so I just kept trying and trying, but nothing was going in.'
Saiki ran off three straight birdies from the fifth to climb to minus-7. She picked up two more birdies on the 12th and 14th, but only parred her last four holes to close a bogey-free round one stroke behind Hurst.
'The whole week I felt really good,' Saiki stated. 'I played the Monday pro- am, which I don't normally do and my team won. My game was really solid.'
Eighteen-year-old Morgan Pressel, who shared the second-round lead with Jang, Jenna Daniels and Candie Kung, struggled to a 2-over 74 to end in a tie for seventh.
Pressel was joined in seventh by Kraft Nabisco champion Karrie Webb, Becky Iverson, Meena Lee, Mi Hyun Kim, Christina Kim and Nancy Scranton.
Kung and Daniels both faltered to 5-over-par 77s at Columbia Edgewater Country Club to end in a tie for 25th at minus-2.