It’s getting tight at the top for Kiwi golf star star Lydia Ko.

The 20-year-old’s grip on the world No 1 ranking has come under increasing pressure from Thai star Ariya Jutanugarn and South Korea’s So Yeon Ryu, with the pair further closing the gap on Ko following the Lorena Ochoa Matchplay event at the weekend.

Ko produced a solid if not spectacular effort in Mexico, wining her opening two rounds before falling to South Korea’s Mi Jung Hur to miss out on the quarterfinals.

However, strong performances in previous years meant she still dropped rankings points, with just 0.3 points separating her from Jutanugarn and and So.

Jutanugarn overtook the Korean into second place after finishing runner-up to Sei Young Kim, with So, who won the year’s first major at the ANA Inspiration, taking the week off.

Ko has struggled for consistency over the last 12 months, overhauling her team during the off-season before dumping caddie Gary Matthews for Peter Godfrey last month.

And perhaps a better indication of her form is the Race to the CME Globe standings, which effectively decides the LPGA’s player of the year.

Ko is languishing at 14th in those rankings, 862 points behind leader So, with Jutanugarn 80 points adrift in second.