Veteran Zheng Jie's opening match was much harder than she expected, but the Chinese world No 40 was happy to be pushed all the way by a teenage compatriot.

What appeared on paper to be a lopsided match against Zhang Yuxuan turned into a grueling three-set battle as Zheng overcame a second-set scare to beat the wild card, 6-1, 3-6, 6-4 in 128 minutes.

Zhang, 18, proved to be a legitimate threat to Zheng, who was broken six times while making 44 unforced errors (three more than Zhang).