On a day when the rising sun flag of Japan not only topped, but completely overtook the first page of the AIG Women’s Open leaderboard, the Australian contingent had some familiar faces lead the charge in pursuit of a women’s major hat-trick.

Eri Okayama and Rio Takeda share the lead after Round 1 at Royal Porthcawl, with Minjee Lee chasing her career grand slam the best of the Aussies after an up and down day concluded with a birdie at the 18th hole to sit 2-under and three back of the lead and in a share 13th.

Gabi Ruffels following Lee’s example two groups behind, with her birdie at the par-5 last rounding out a back nine of 3-under 33 having turned in 2-over. The Victorian’s 1-under round matched by Amundi Evian Championship winner Grace Kim.

The next best of the Australians is Steph Kyriacou on 2-over after a frustrating day with the putter saw her headed straight for the practice green with a short turnaround before her second round.

Lee, who at 29 is the oldest of her countrywomen teeing it up in Wales, believes her experience was crucial during a grinding opening round, where the wind was up then down, occasional showers came and went, and play took longer than anyone would have hoped.

Birdieing the second, Lee immediately gave the shot back at the next, before birdie at the uphill par-5 ninth got her back under par. Playing in front of some of the biggest morning crowds with Charley Hull and Jeeno Thitikul, another birdie at the 11th meant Lee looked ominous given her recent major form.

Finding a greenside bunker at the par-5 13th Lee splashed out but misjudged a first putt that hit the lip and left a tester for par that also hit the edge of the hole and spun around and out. Lee’s bogey six slightly stalling her charge.

“That was a little bit of a silly mistake. Kind of misjudged the speed down that little hill and then had three or four feet back up the hill for par,” Lee said.

“I'm going to make a mistake … bounced back pretty well. Just trying to keep myself in it.”

Earning the shot back with birdie at the par-3 15th, there was another momentum sapping bogey at the very next hole before Lee managed to avoid repeating her error of the 13th with a bunker shot at the par-5 18th delivering birdie and an overall satisfied world No.5.

“I mean, it was difficult, setup a little differently than what I thought it was going to,” she said.

“The tees were up a little bit, but some of the holes it made it harder because you couldn't hit driver off the tee.”

“I don't think I'm going to complain with a 2-under start. Some of the holes are just beasts out there. It's a major championship. You're going to make bogeys. Just try to keep your emotions in check and take it one shot at a time.”

Known as an elite ball striker, Ruffels’ putter was the issue on her outward half, before the Victorian changed strategy with her fellow ‘tennis kid’ and temporary caddie, Zara Woodbridge, assisting with green reads on the back nine.

“She's one of my really good friends. It just feels like fun out there. It feels like a round with your friends. I love that feeling. She's been great,” Ruffels said of her temporary looper who only had one error when a headcover was temporarily left behind.

“I played a lot of golf with her and we played a lot of golf together and we know each other's games pretty well. She's a good putter. When the putts weren't dropping on the front, I kind of got her refocused on the back and it worked out well.”

The change leading to more success on the greens as Ruffels made birdies at both back nine par-3s, 12 and 15, as well as at the last to sign for 71 and a tie for 30th at the end of the day.

“I don't think it's going to be super easy out here. 1-under, I'm definitely in it. Looking forward to tomorrow,” was Ruffels summary of her day.

Playing in a marquee group of major winners after her success in France earlier this month, Kim was solid if not spectacular, with her best chance at a highlight moment when putting from the front of the 17th green to the back and only missing her birdie by one roll of the golf ball.

“The wind did pick up certain holes, the sun came out, and then it disappeared … just the amount of wind was up-and-down throughout the day,” Kim said.

“Knowing that, really just trying to hit fairways and greens and just make a lot of pars.

“This whole week, literally I think the best word to describe it is a grind.”

The Sydneysider carrying some extra reminders of her recent elevation to major champion status during the round, choosing not to carry this week’s tournament provided water bottle, but instead still using the Evian branded version.

“I just haven't switched it out. The Evian bottle works just fine,” Kim said with a laugh.

The trio of New Zealanders had their moments on Thursday too, with Lydia Ko following Minjee’s misfortune of a lip out and bogey on 13 during the defending champion’s 1-over start, while Momoka Kobori began her major career with a respectable 2-over round of 74 matched by Amelia Garvey.

For the rest of the Australians there is work to do to get more than two rounds of competitive golf at Royal Porthcawl, with Kyriacou sitting outside the projected cut while Karis Davidson fought back hard from 6-over through her first eight holes to eventually finish 4-over.

Kirsten Rudgeley was without a birdie in her round of 78 (+6), whereas pars were elusive for Hira Naveed in her 6-over debut at the Women’s Open.

Meanwhile, it was a day to forget for Hannah Green, who would have only finished 3-over for the day if not for a triple bogey eight at the par-5 ninth. The ninth also the undoing of Cassie Porter who is 7-over.

Australasian Scores T13 Minjee Lee, -2 T30 Grace Kim, -1 T30 Gabi Ruffels, -1 T74 Lydia Ko, +1 T91 Steph Kyriacou, +2 T91 Momoka Kobori, +2 T91 Amelia Garvey, +2 T111 Karis Davidson, +4 T134 Kirsten Rudgeley, +6 T134 Hira Naveed, +6 T139 Hannah Green, +7 T141 Cassie Porter, +7

All four rounds of the AIG Women's Open will be broadcast live on Fox Sports and Kayo.