World No. 1 Lydia Ko fired a sensational course record 10-under-par 62 to power into a three-shot lead at the halfway stage of the season-ending LPGA Tour Championship Friday. The teenager from New Zealand blasted 11 birdies on her way to taming the 6,450-yard layout at the Tiburon Golf Club in Naples, Florida. It was an extraordinary performance from the 19-year-old, whose round might have been even better had it not been for a bogey on the par-three 12th. Ko needed only 22 putts to compile her round, which followed a first-round 70 Thursday which saw her start the day at two under. Ko's majestic display left her sitting on 12-under, a 36-hole aggregate of 132, three shots clear of Ryann O'Toole and South Korea's Soyeon Ryu, both at nine under. Beatriz Recari and Kim Sei-young were a further shot back on eight under after carding matching 68s. Jessica Korda and Mariajo Uribe climbed into a four-way tie for sixth place at seven-under after shooting 66s. China's overnight leader Feng Shanshan slipped down the leaderboard however after a one-over-par 73. Feng is seven back from Ko on five under. But the day belonged to Ko, who opened her second round with three consecutive birdies and never looked back. "Going into today my goal definitely wasn't a 62," a delighted Ko said. "But the first few holes gave me a really good momentum and I was able to carry that for pretty much the rest of the round. "I was putting good so whenever I was within a distance that felt comfortable I was thinking, ‘Hey, I could hole this.' "It was just that kind of a day. When you see the putt it just feels like the ball's going to feed into the hole." Ko's round leaves her firmly on target to claim victory in the $2 million tournament. A win this weekend would also see her clinch the CME Globe title, the LPGA Tour's points race, which would earn her another $1 million bonus. Her two closest rivals in the points race — which Ko has won for the past two seasons — finished the second round well down the leaderboard. Thailand's Ariya Jutanugarn, the CME Globe points leader, is eight shots off the lead after a four-under-par second-round 68. Canadian teenager Brooke Henderson was unable to improve on her level-par first round, firing another 72 to remain at even, 12 shots adrift of Ko. Ko however said she would not allow herself to be distracted by the points-race permutations. "I think the key mindset for me has been not thinking about everything that could happen," she said. "I know that for me to win player of the year I need to win this championship. "For me it's more important to make sure I finish my season strong so I don't feel the pressure."