Ana's three-day first round match against Ayumi Morita in the PTT Pattaya Open ended in a disappointing 6-3, 5-7, 6-3 defeat for the top seed.
Ana was broken in the first game following the resumption of play and Morita surged to a surprise victory.
The 25-year-old's next tournament is the Qatar Ladies Open, which begins in Doha on 11 February.
