At just 16 years, 7 months and 8 days old, she won the Navistar LPGA Classic by five strokes over Tiffany Joh.
Before Thompson's win, Marlene Hagge held the record for the youngest winner on the LPGA Tour. Hagge was 18 years, 14 days when she won the 1952 Sarasota Open, an 18-hole event.
Prior to Thompson's victory, the youngest winner of a multi-round event on the LPGA Tour had been Paula Creamer, who captured the 2005 Sybase Classic when she was 18 years, 9 months and 17 days.
But that isn't the only record Thompson has broken.
In 2007, she became the youngest qualifier for the U.S. Women's Open at the age of 12.
That same year she won the 32nd Junior PGA Championship to become the youngest winner in Junior PGA Championship history.
Thompson, who went on to win a second Junior PGA Championship title in 2009, had already become the youngest to ever compete in the Championship in 2005, when she was only 10-years-old.
In 2009, the then 16-year-old Thompson cruised to a 12-stroke triumph, one stroke off the all-time record, closing with a final-round 5-under-par 67 and 272 total. Thompson's rout trails only Debbie Hall, who posted a 13-stroke victory in 1977.
The Junior PGA Championship -- A History of Showcasing Tomorrow's Stars
One of golf's major championships for juniors, the Junior PGA Championship is where the best in the world get their start.
Begun in 1976, at Walt Disney World Resort in Orlando, Fla., the Championship has been a popular stop on the national junior circuit for many of today's PGA and LPGA touring professionals.