Top seed Sorana Cirstea of Romania struggled past wild card Ons Jabeur of Tunisia 6-3, 6-3 to open her account in the Baku Cup on Tuesday.
Cirstea previously had trouble with Jabeur in Doha last year. This time, they shared 15 double faults and 11 service breaks before Cirstea prevailed.
Elina Svitolina of Ukraine, who won her maiden WTA title her last year and was back as the No. 2 seed, defeated qualifier Nigina Abduraimova of Uzbekistan 6-2, 6-4.
However, three seeds lost: No. 3 Magdalena Rybarikova of Slovakia to qualifier Misa Eguchi of Japan, No. 4 Kurumi Nara of Japan to Francesa Schiavone, who landed less than half of her first serves, and No. 7 Heather Watson of Britain to Kristina Mladenovic of France, who leads their head-to-heads 3-2.