The 18-year-old Hurst, the tour's player and rookie of the year, had a 2-under 211 total on the Chateau Elan Golf Club course.
The victory counts as an official win, but the $21,000 winner's share is considered "unofficial" and doesn't count in her season total. She also was awarded $5,000 from Duramed for her season accomplishments.
"I wanted to play a great tournament and I just tried to stay focused all week," Hurst said. "This was my chance to prove to myself that I've worked hard all season."
Hurst, from Melbourne, Fla., holed a 20-foot par putt on the 16th hole to break a tie with Laing. She birdied the 17th to take a two-stroke lead, then bogeyed 18.
"When I made the putt on No. 16, I felt like I was going to win," Hurst said. "After I made that putt, I felt like I was ready for the LPGA Tour. The 17th hole is probably the toughest hole we've had to play all year."
She also won events in McAllen, Texas; Decatur, Ill.; Hammond, Ind.; and Bloomfield, Conn., and led the money list to top the tour's 2009 LPGA Tour qualifiers.
"For it to be my last Duramed Futures Tour event and see the staff members and the players for the last time, it was pretty special to get a win," Hurst said. "The journey isn't over for me. I want to stay focused on the future and not look back."
Her mother, Koko, doubles as her caddie.
"Mom and I are a great team," Hurst said. "I didn't do it - we did it."