Laura Robson celebrated becoming British number one for the first time with a victory in China on Monday.
Just hours after becoming Great Britain's top player by rising to a career-high 74th in the WTA rankings, Robson saw off Maria-Teresa Torro-Flor at the RC Bank Guangzhou International Open.
The 18-year-old, who upset former Grand Slam champions Kim Clijsters and Li Na en route to the last 16 of the US Open recently, was leading 6-2 3-1 when her Spanish opponent retired with a thigh strain.
Robson, who is now one place above compatriot Heather Watson in the WTA list, is likely to face Chinese second seed Jie Zheng in the second round.
Robson becomes the fourth holder of the British number one ranking this season after Watson, Anne Keothavong and Elena Baltacha.
Keothavong, currently the British number three, had also been due to compete at the Guangzhou tournament but she has been forced to withdraw due to a foot injury.
Meanwhile, fifth seed and defending champion Chanelle Scheepers thrashed wild card Wang Qiang 6-0 6-3, while there were also wins for Bojana Jovanovski and Mandy Minella on Monday's opening day.
