(Reuters) - After a dose of positive reinforcement, Lydia Ko aced her second round at the season-ending CME Group Tour Championship with a tournament record 62 that catapulted her into a three-shot lead in Naples, Florida, on Friday.

Ko was seen working into the night on Thursday with instructor David Leadbetter after carding an opening 70 that left her four strokes behind pace-setter Shanshan Feng of China.

The 19-year-old New Zealander said a video he showed her of her first career hole-in-one at the Olympics in Rio sparked her 10-under-par round on Friday at Tiburon Golf Club.

“Brings back a lot of great memories," said world number one Ko, the Olympic silver medallist who has gone without a victory in her last nine events. "It was something I couldn't ever have dreamed of.

“To see that swing, you know, I was hitting the ball really well at the Olympics. It gave me all the positive thoughts."

Ko posted 11 birdies, starting the round with three in a row and registering seven on the back nine against a lone bogey, taking just 22 putts to reach 12-under-par 132.

Sharing second on nine-under were South Korean Ryu So-yeon (67) and American Ryann O'Toole (68).

Feng, winner of her last two events, struggled to a one-over 73 to stand tied for 16th at five-under.

A win at Tiburon would give Ko her third successive $1 million bonus for winning the Race to the CME Globe points chase, and would clinch Player of the Year honours over Thai Ariya Jutanugarn.

Jutanugarn, a five-time winner this season, shot 68 on Friday after an opening 72 to stand four-under.

(Writing by Larry Fine in New York; Editing by Peter Rutherford)