PORTHCAWL, Wales :Japan's Miyu Yamashita surged into the lead at the AIG Women's Open with a superb second round seven-under 65 at Royal Porthcawl on Friday, with compatriot and joint overnight leader Rio Takeda three shots adrift.England's Lottie Woad, the bookmakers' favourite despite the tournament being her first major as a professional, mounted a charge but a triple-bogey at the 16th meant she carded a two-under 70 to be nine shots adrift at the halfway point.Reigning champion Lydia Ko of New Zealand was in grave danger of missing the cut after a disappointing round of 73 left her two over for the tournament. Definitely missing the weekend is 2023 winner Lilia Vu who finished at seven over par.World number one Nelly Korda struggled with her putting in an even-par 72 round that left her level with Woad.Yamashita took full advantage of the tranquil early morning conditions on the South Wales coast, setting the tone for a scintillating round with birdies at her opening two holes.Three more birdies around the turn, another at the 13th and then a final flourish at the 18th where she sank yet another birdie putt meant she walked off with a commanding lead ahead of freshening winds expected for the later groups.Takeda, who began the day on five-under alongside compatriot Eri Okayama, slipped back with a bogey at the sixth but a tap-in eagle at the par-five ninth got her back on track.Two more birdies on the way back in kept this year's U.S. Open runner-up on the heels of Yamashita.Okayama was teeing off her second round later.SENSATION WOADOnce again, the galleries flocked to see new sensation Woad in action as she set about making a move up the leaderboard.The 21-year-old began in steady fashion before the birdies began to flow with four in five holes, including a majestic long putt on the 14th.But her momentum hit the buffers at the tough 16th where her second shot found thick rough and after attempting to hack out she then took a drop on her way to a seven."I was angry after that but I had to move on quickly," Woad, who missed a birdie putt at the 18th, told Sky Sports."I'll try and put a good round together tomorrow and limit the mistakes, which I did today until the 16th."American Lindy Duncan shot a 70 to be four-under for the tournament while Sweden's Madelene Sagstrom was a further stroke back in a group on three-under after a 69 fired her upwards.Australia's Steph Kyriacou provided the fireworks with a wild round that included a hole-in-one at the eighth. She had only one par on the back nine, making two birdies, five bogeys and a chip-in eagle at the 18th to make the cut.