The 22-year-old Sydney-born, Queensland-raised prospect, who didn't make the cut in her first event at the Founders Cup last month, coped superbly with the windy conditions to shoot a four-under par 68 and join Japan's Nasa Hataoka atop the leaderboard on Friday.
After six-time Japanese tour winner Hataoka shot a six-under 66 -- the best round of the day -- she and Porter were both on a seven-under total of 137 after two rounds, just a shot clear of the field.
Japan's Rio Takeda was their nearest challenger after a 69, while Mexican Gabbie Lopez (70) and American Auston Kim (71) were two back.
It was a terrific start for Porter, who had even considered pulling out of the event before Thursday's first round as she was suffering with a flu bug.
But she followed up her opening round of 69 with an even better effort, featuring five birdies and a solitary dropped shot.
"Yeah, I'm feeling okay. Being a little sick has kind of helped me a little bit, just slowed me down a little," she explained afterwards.
"I always say I get pretty quick if I'm stressed or anything, so it's kind of forced me to slow down."
Leading at halfway didn't exactly faze Porter, though.
"It's great. I'm just having fun out here, really. It's always the goal to be in contention, so I'm not too surprised," she said.Â
"We work for this, and it's nice to see some hard work paying off. But there's a lot of golf to play..."
Porter even outshone her illustrious compatriot, two-time major winner Minjee Lee, who was still well-placed at two under, tied for 15th place, after a 72, while another in-form Australian was Hira Naveed, who was joint-eighth on three under following a 70.
Jeeno Thitikul, the LPGA's No.2-ranked player, went round in 73 to sit five off the lead.
