The second-seeded Belgian, now down at 59 in the rankings, was expected to coast past home favourite Chan Chin-wei but met with stiff resistance in their 83-minute encounter.
Wickmayer claimed the opening set on a tie-break before edging the second to secure a 7-6 (7/3) 6-4 win against qualifier Chan.
Two seeds exited on Tuesday with number five Kurumi Nara and number six Caroline Garcia losing their first-round clashes.
Nara went down 6-3 7-5 to Germany's Anna-Lena Friedsam while Slovakian Anna Schmiedlova proved too strong for Garcia, winning 6-7 (3/7) 6-1 7-5.
There were also wins on day two for Olga Govortsova, Luksika Kumkhum, Petra Martic and Zheng Saisai.