Today in Sports – Lydia Ko, 17, becomes the youngest golfer, male or female, to be ranked No. 1

1998 — Martina Hingis, 17, becomes the youngest player in the Open era to defend a Grand Slam title, capturing her second Australian Open with a 6-3, 6-3 victory over Conchita Martinez. 2009 — Serena Williams routs Dinara Safina 6-0, 6-3 to win the Australian Open — her 10th Grand Slam title — and return to the No. 2010 — Roger Federer beats Andy Murray 6-3, 6-4, 7-6 (11) for a fourth Australian Open championship and his 16th Grand Slam title overall. 2015 — Serena Williams wins her 19th Grand Slam title and extends her decade-long domination of Maria Sharapova with a commanding 6-3, 7-6 (5) win. 2015 — Lydia Ko, 17, becomes the youngest golfer, male or female, to be ranked No.