The ninth-ranked Indian let go of three match points in the deciding game before pulling off a 23-21, 6-21, 22-10 win over the World No 12 from Indonesia.
Nehwal, however, won her second-round match rather convincingly. The Olympic bronze medallist, who has dropped to 27 in the latest World rankings, registered an easy 21-15, 21-17 win over second-seeded Yamaguchi.
The 28-year-old Indian Will now take on World No 3 and another Japanese, Nozomi Okuhara, in the quarter-finals on Friday.
This was Nehwal’s second career win over Yamaguchi, who has won six times in the head-to-head encounters between the two. Nehwal’s first win against Yamaguchi came in 2014 during the China Open.
Nehwal trailed 0-4 initially but she made a fine comeback to level the scores at 10-10. But from there, Nehwal showed off five straight points to take a 15-10 lead and then widened it to 19-12. Yamaguchi recovered a bit but Nehwal grabbed five-game points at 20-15 and then easily pocketed the first game.
In the second game, it was Nehwal’s turn to take the lead initially as she zoomed to 7-2 but Yamaguchi caught her up at 11-11. After that, it was a close tussle between the two as they were locked at 17-17.
At that stage, Nehwal cinched points on the trot to win the second game and clinch the match.
It was a good day for India in the women’s doubles as well with Ashwini Ponnappa and N Sikki Reddy upsetting seventh seeds from South Korea, Lee Ho See and Shin Seung Chan, 18-21, 22-20, 21-18 to enter the quarterfinals.