Lydia Ko became world No. 1 when she was only 17 -- four years younger than Tiger Woods when he claimed the top spot for the first time.
Ko is flanked by an honor guard of Royal Canadian Mounties after her record-breaking win at the 2012 CN Canadian Open. At just 15 years and four months, the New Zealander became the youngest winner of an LPGA Tour event.
Ko returned to Canada in 2013 to repeat her groundbreaking success aged 16 -- this time becoming the youngest to win two LPGA tournaments.
Even before she had become a teenager, Ko was a force in amateur tournaments in New Zealand, here taking part in an event in 2009 aged 11.
In 2012, she became the youngest person ever to win a professional golf event, taking the New South Wales Women's Open aged 14.
Before turning professional in October 2013, Ko (pictured here alongside Stacy Lewis at the British Open) was the top-ranked women's amateur for 130 consecutive weeks.
Ko won her third LPGA Tour title, the 2014 Swinging Skirts Classic, at Lake Merced Golf Club in California -- a course she'd go on to know very well.