Thompson carded a four - under - par 68 for a 20 - under total to register a seventh LPGA Tour win of her career and third title since July .
Thompson started the final round with a four - stroke advantage .
Thompson , who started the final round with a four - stroke advantage , carded a four - under - par 68 for a 20 - under total to register a seventh LPGA Tour win of her career and third title since July .