Ryu So-yeon shot a tournament-record 10-under-par 61 on Saturday to seize a five-stroke lead heading into the final round of the Walmart NW Arkansas Championship here. Ryu, who is bidding for her second LPGA title this year and fourth of her career, finds herself at 16-under 126 to claim the 36-hole record at the tournament. The 26-year-old South Korean capped her impressive bogey-free round with back-to-back birdies, finishing with 10 on the day to claim comfortable lead over Thailand's Moriya Jutanugarn and American Stacy Lewis at Pinnacle Country Club. "It was so much fun," Ryu told reporters after her round. "I made a really long putt at 8, 17, and then I boost up and the shot was getting better and better. At the back nine, I was able to make some more short birdies, and then pretty much made all of them. So happy with my round today." Ryu resides third in the Rolex world rankings and is .489 average ranking points behind No. 1 Ariya Jutanugarn, who isn't playing this week. If Ryu wins, the battle for No. 1 likely will come down to fractions of a point in Monday's release of the new rankings. Ryu's performance on Saturday bested the previous course record of 62, set by Angela Park and Jane Park in 2008 and matched last year by Lydia Ko and Ayako Uehara. Both Jutanugarn and Lewis each followed their opening-round 66s with seven birdies against one bogey to finish with a 65 Saturday. Lewis capped her round with back-to-back birdies at the par-3 17th and par-5 18th to send the crowd into a frenzy. "Kinda felt like I was struggling a little bit coming in, so that's why the last two birdies were extremely important to me," Lewis said. "I felt like I got the momentum back and can hopefully post another good one tomorrow." South Korean's Amy Yang shot a 65 to sit in fourth place at 10-under, one stroke ahead of the four-way contingent of countrywoman Inbee Park (65), Australian Minjee Lee (65), Indian Aditi Ashok (64) and Norwegian Suzann Pettersen (66). — Reuters