Kirilenko handled Ukrainian Alona Bondarenko 6-4, 6-2, while Gajdosova continued her winning ways at this hardcourt event with a 6-2, 6-1 pasting of China's Han Xinyun at Tianhe Sports Centre.
Up next for Kirilenko will be France's Iryna Bremond, while Gajdosova will encounter Luxembourg's Mandy Minella.
Gajdosova beat Russia Alla Kudryavtseva in last year's Guangzhou finale.
A Day-2 upset came when China's Yung-Jan Chan got past third-seeded Russian Ksenia Pervak 4-1, retired. Pervak was fresh off her first career WTA title last week in Tashkent.
More upset came when Ukrainian Tetiana Luzhanska upended fifth-seeded Serb Bojana Jovanovski 6-3, 4-6, 7-6 (7-4) and Chinese favorite Zheng Jie ousted sixth-seeded Italian Alberta Brianti 7-6 (7-3), 6-4. Brianti was the runner-up here two years ago.
Two other seeds avoided upsets, as No. 7 Chanelle Scheepers of South Africa held off Latvian Anastasija Sevastova 7-5, 1-6, 6-3 and No. 8 Magdalena Rybarikova of Slovakia snuck past 37-year-old American Jill Craybas 6-3, 4-6, 6-2.
Several other women reached the second round, including France's Aravane Rezai, qualifier Su-Wei Hsieh of Taipei and Chinese qualifier Yi-Jing Zhao.
The 2011 Guangzhou titlist will collect $37,000.