“There is a pain, I couldn’t move properly so that’s why I stopped,” Halep, who suffered a shock early exit from the recent US Open, said.
“I don’t know exactly what it is. I will go home, I will have an MRI (scan) and I will see.”
“I’m just worried now, I feel sad that I couldn’t finish,” Halep added, saying that she feared playing was making the problem worse and she knew from the start of the match that she was struggling.
Halep believes it is a different back problem from the one that contributed to her early loss in Wuhan.
“I knew that there is pain, but I thought if I warm up during the match, it’s going to be better, but it wasn’t,” she said.
Holder Caroline Garcia survived a major scare before defeating wildcard Wang Yafan 7-6 (12/10), 6-7 (4/7), 6-3 to open the defence of her crown.
The 24-year-old from France defied a rattling roof and a surprisingly stiff challenge from the home player to labour into round two on Beijing’s hard courts after more than three hours of nervy action.
Garcia took the first set on a tie-break after 77 minutes during which the retractable roof — which was closed — banged noisily on occasion in the wind.
The fourth-ranked French player and Wang, 78th in the world, went to battle again in the second set and Garcia came back to force another tie-break.
Garcia, who won back-to-back titles last year in China in a breakthrough 2017, rescued one set point in the tie-break but Wang made the second count to force a deciding set.
Garcia was more ruthless this time, racing into a 3-0 lead as the 24-year-old Wang’s fighting spirit was finally nullified.
“Compared to the previous year, I didn’t take my chances,” Garcia said, reflecting on her “disappointing” 2018 compared to her stellar 2017.
“You know, it’s a complicated year, a lot of ups and downs.”