A stomach bug nearly prompted golf sensation Lydia Ko to pull out of the New Zealand Women’s Open before she carded a second-straight 69 to sit two shots off the pace.

Defending champion Ko went nearly 24 hours without eating after falling ill soon after her opening round at Clearwater Golf Club on Friday afternoon.

New Zealand’s world No.4-ranked player skipped dinner, breakfast and lunch before experimenting with some snacks midway through Saturday’s second round.

Her playing partner in the final round of the 54-hole tournament will be tournament leader Anya Alvarez, whose sizzling 66 lifted her to eight-under-par.

“The most important thing I did today was stay calm when I started feel a little bit excited that I was playing well,” the US 24-year-old said.

“Now I have to keep my head in the game. There are 18 holes to play and I have to work really hard.”

Jessica Speechley was in joint sixth position while fellow Australian Stacey Keating was in eighth spot.

Australian Sarah Jane Smith dropped from equal third on Friday to 42nd spot.

Auckland 16-year-old Ko sought a hospital diagnosis on Saturday morning and was given medicine to treat some “extra wind” in her system.

“I was really sick. At one stage, I was going to withdraw but luckily I didn’t,” she said.

Florida-based Alvarez, the daughter of former US PGA pro Alex Alvarez, says she is looking forward to comparing her game with that of Ko in a pressure situation.

“When I was 16, I was into boys and shopping and not really focused on anything in life so I really admire her.”

Ko sits one shot clear of a group on five-under comprising American Beth Allen and Koreans Seon Woo Bae and Kyu Jung Baek.

She is unconcerned about the margin to Alvarez, hoping she is physically well enough to launch a challenge for the lead in front of what is expected to be a large and expectant home gallery.

“Two shots can happen over a hole. It seems like she’s playing really well but I’ve just got to play my own game,” said Ko.