Sixteen-year-old Lexi Thompson came into the final round of the Navistar LPGA Classic with two things going for her: a five-shot lead playing the course where she scores best on the LPGA. With a steady hand most of the day and great approach play when she needed it most, Thompson became the youngest winner in the history of the tour. Thompson cared a final round 2-under 69 to finish on 17 under par. She won in Alabama five clear if Tiffany Joh, unseating Paula Creamer as the youngest winner by some two years. Thompson did so six years after Creamer won the Sybase Classic. . Getting out of the gate early, Thompson made a birdie at the par-3 second hole. With another birdie at the eighth, Thompson led by seven at the turn. Joh made a run at the teen on the back nine at the Capitol Hill Senator Course with four consecutive birdies from 12 through 15. Thompson responded with birdies at the 16th and 17th to lock up the win. Thompson is not currently a member of the LPGA and had been planning to compete in the second stage of Q-School at the end of the month. Since she is under the age floor of 18 for membership, Thompson had to seek and was given special dispensation from commissioner Mike Whan to attempt qualification. With the win, Thompson will have to do the same to become a member as well. Now, however, she will carry a two-year exemption with her status