The eight-seeded Indian lost 10-21, 17-21 to World No. 8 in just 44 minutes at the Olympic Sports Center Xincheng Gymnasium. It was her second consecutive defeat against the Thai shuttler.
China Open has been one tournament where Saina has had a decent outing in the past. The 29-year-old triumphed Changzhou in 2014 and went on to reach the final the very next year, where she fell to 2012 Olympic champion Li Xuerui.
However, on Wednesday, the London Olympic bronze medallist didn't seem to be in any sort of rhythm as out of the 69 points played, she could only manage to win 27 while the remaining 42 went to Busanan's way.
2019 hasn't been a great year for the former World No.1. Ever since her comeback from injury, things haven't panned out the way she would have liked. Having played the New Zealand Open in May, she was forced to stay away from the court for more than two months due to fitness issues.
When she made a return at the Thailand Open, Saina, who was only the second Indian to be World No. 1 after Prakash Padukone till then in 2015, managed to win just one match before bowing out to Sayaka Takahashi.
At the World Championships held in Basel, Switzerland, she made a second-round exit as she went down to Mia Blichfeldt.
The only competition she won was the Indonesia Masters in January where she defeated Olympic gold medallist Carolina Marin, who was forced to retire in the summit clash.
( With inputs from IANS )