World number one Lydia Ko beat hometown favorite Ana Menendez 3 & 2 on Thursday to launch her campaign at the LPGA Lorena Ochoa Match Play, where Ariya and Moriya Jutanugarn set up a second-round sister duel.

New Zealand's Ko, who was forced out of last week's Texas Shootout with an eye infection, was the first winner of the day in the tournament that switched this year from its former stroke play format.

She seized the lead with a birdie at the par-five second, and was able to take advantage of some miscues by Menendez -- who won two holes with birdies but never got ahead.

Ko won the 14th with a par to go 3-up and sealed the win when they halved the 16th with birdies.

"Hopefully, that last birdie is good momentum going into tomorrow," Ko said. "Playing with a hometown girl you know one of the favorites I knew that it was going to be a tight one and it was fun.

"Match play is definitely a different game to stroke play," she added. "I enjoyed it, but you just never know."

Ariya Jutanugarn, the top seed in her bracket, advanced with a 5 & 4 win over Amy Anderson while eighth-seeded Moriya beat Alana Sharp 2 & 1.

"We talked about (playing each other) after we saw the pairing," Ariya said. "We said we are lucky we hadn't booked a flight yet. We never know who is going to go back early so we are happy about that."

The Thai sisters were paired together in the final round of the Texas Shootout, but Ariya said they had faced each other in match play only once, in an amateur event in Canada.

"We always try to be ourselves so she's probably going to say that she's going to go out there and play her best, so I say I'm going to play my best," Moriya said.

Belgium's Laura Gonzalez Escallon, the 16th seed in her bracket, notched the biggest upset of the day -- a 2 & 1 victory over two-time major champion Chun In-Gee of South Korea.

Gonzalez Escallon won four holes with birdies, including the winning putt on the 17th.

"I am excited with this win -- the odds were completely against me," said the Belgian, who played university golf in the United States and graduated to the LPGA tour from Symetra Tour.

England's Charley Hull overcame a fainting spell and a two-hour delay because of lightning to post a gritty 2 & 1 victory over American Nelly Korda.

"I felt really faint on the 12th fairway and I just kind of collapsed... I kept seeing flashing lights and that's when the medics came out," Hull said.

"I was a bit low on blood sugar so they gave me some Pepsi and a syrup with lots of sugar in it. I started feeling a little bit better but I still felt sick."

source: AFP