World No 1 amateur Lydia Ko has played superbly on day two to qualify for the quarter-finals of the US Girl's Junior Amateur Championship at the Lake Merced Golf Club in California overnight. (NZT)
Ko, who qualified as the No 2 seed, was quick into her work this morning when she dismissed Californian Hee Wook Choi (31) by 7 and 6 to match her margin of victory from round one.
In round three, the Gulf Harbour player was in a good battle with Nicole Morales from New York and the pair was all square through the opening five holes.
But the world's best amateur soon found her rhythm and was never behind again in the match.
The 15-year-old won the sixth hole to go 1up, and then doubled her advantage on the 11th. Morales was back in the match when Ko bogeyed the par 3 15th. But she restored her advantage on the following hole with a birdie. She held on to win by 2 and 1 and make the final eight players.