New Zealand’s Lydia Ko says it’s “pretty awesome” to have ascended to the top of world golf, a feat she has done faster than any player – male or female – in the game’s history.

The 17-year-old from Auckland missed out on winning the season-opening LPGA event in Florida on Saturday, but tying for second was enough to climb to No.1 in the world rankings.

Korean Na Yeon Choi won the tournament.

Ko leapfrogs Korean Inbee Park, who finished tied for 13th at the $US1.5 million ($A1.93 million) tournament, to become the youngest player of either gender to hold the top status.

Ko says she didn’t know it was going to happen and doesn’t really understand how the rankings work.

“Today I was just trying to focus on hitting good shots and that’s all I can really do out there,” she said after the tournament.

“Obviously I didn’t win at the end of the day, but I still became world number one and that’s pretty awesome.”

Prime Minister John Key, a keen golfer, tweeted his congratulations to Ko for her “fantastic achievement!”

The previous youngest woman was Korean Jiyai Shin, who was 22 when she rose to the top in 2008, while American great Tiger Woods set the men’s record aged 21 in 1997.

Ko, who turns 18 in April, won three LPGA titles in her rookie season last year and her gutsy triumph at the Golden Ocala course is her sixth in total.

Starting the final round one shot ahead of a tightly packed group, she sank long birdie putts on the first two holes to surge four strokes clear.

However, she lacked momentum from there, with a bogey on the par-four eighth hole allowing Korean playing partners Choi and Ha Na Jang to turn the tournament into a tight contest over the closing nine holes.

Choi snatched the lead with a birdie on the 14th hole before Ko hit a birdie on the 15th and par on the 16th.

Ko shot a double bogey on the 17th, but finished with par on the 18th.

She finished the tournament 15 under in a three-way tie for second with Jang and American Jessica Korda.

The trio were one-shot behind winner Choi.

Korean Amy Yang came in third six shots behind Choi.

Last year Ko had 15 top-10 finishes and pocketed more than $US2m in prize-money.

This week was her first tournament played without her trademark glasses, showing no ill-effects from a switch to contact lenses.

She is scheduled to contest the LPGA Classic in the Bahamas next week ahead of the national opens in Australia and New Zealand.