Nara reaches Japan Women's Open quarters
Kurumi Nara of Japan hits the ball in Tokyo on September 22, 2013
The 21-year-old Osaka student, ranked 87th in the world with no tournament title to her name, needed almost two hours to tame the 48th-placed Puig, one year her junior.
Nara will face Slovenia's Polona Hercog who reached the last eight when her second-round opponent, second seed Sabine Lisicki of Germany, pulled out with a lower back injury.
In other second-round matches, third seed Samantha Stosur of Australia, the 2011 US Open champion, ousted Swiss qualifier Belinda Bencic 6-4, 6-2 and No. 5 seed Eugenie Bouchard of Canada defeated Thailand's Luksika Kumkhum 6-2, 6-2.
Czech Barbora Zahlavova Strycova battled from behind to whip Vania King of the United States 2-6, 6-3, 6-1.
It was Nara's fifth straight appearance in the Japan Women's Open and the first time that she reached the quarter-finals of a tournament carrying total prize money of $235,000 or more.