In an evenly contested affair, breaks at the start of the first set and end of the second proved decisive as World No.157 Zheng secured a 64 64 win.
Aside from a trip to New York for the US Open, Zheng has played almost exclusively in her native China in the second half of the year, posting some positive results. The highlight was a run to the final at the WTA 125K Series event in Suzhou, where she lost to former World No.11 Shahar Peer in the final.
After almost slipping out of the Top 500 following a lengthy bout of glandular fever, Tomljanovic has been one of 2013's success stories, flying up the rankings thanks to a number of encouraging showings on both the full tour and ITF Circuit.
Now at a career-high ranking of No.79, Tomljanovic is the No.7 seed in Nanjing, and saw off Olga Puchkova, 64 64, in the first round to continue her winning ways.
No.8 seed Schmiedlova was also made to work for her second round spot, recovering from a break down in both sets to defeat Risa Ozaki, 75 64.