25-time Grand Slam champ Martina Hingis retires for 3rd time

Swiss tennis player Martina Hingis has announced she will retire for the third and "final" time at the end of this week's WTA Finals. The 37-year-old, who previously announced retirements in 2003 and 2007, has won 25 Grand Slam titles across all categories in her 23-year-long career, and also played alongside Sania Mirza, winning three Grand Slams together.