In the first game, Saina was leading 11-7 before the World No. 10 staged a superb comeback. Though Saina had three game points at 20-17, Inthanon drew level with forehand smashes and brilliant net play. However, the London Olympics bronze medallist responded with two brilliant shots to win the game.
Saina then won four points in a row to seize the initiative in the second game but Inthanon refused to throw in the towel. The three-time world junior champion matched Saina smash for smash and drop shot for drop shot. The Thai teen even inched ahead to 11-8.
It was at this stage that the 22-year-old Indian champion showed her class. Saina was just one point away from winning the second game when Inthanon restored parity.
However, the World No. 3 was not willing to let the match stretch into the third game. The Hyderabadi player came up with two smashes to set up a rematch with German shuttler Juliane Schenk whom she defeated recently to win the Denmark Open.
Saina has so far won four titles this year including two Super Series badminton championships.
In another quarter-final, young Chinese player Chen Xiao Jia gave her all against the fourth seed. Despite this, Schenk's experience proved to be the deciding factor as she easily won 21-10, 21-14.