No. 1 seed Cibulkova saw off wildcard Fanny Stollar 6-3, 6-3 Wednesday while second seed Zhang advanced to the last 16 in Budapest with a 6-3, 6-2 win against Arina Rodionova.

Cibulkova next faces Kirsten Flipkens, who beat Monica Niculescu 6-4, 7-5. Zhang takes on Jana Cepelova following the qualifier's 6-2, 6-2 triumph over Carina Witthoeft.

Defending champion Timea Babos made light work of her first round opponent Tatjana Maria.

Babos, who claimed a career-third WTA title at the Taiwan Open recently following doubles success at the Australian Open, cruised into round two with a 6-1, 6-0 victory and dropped just three points against Germany's Maria. Babos will take on Germany's Mona Barthel next.

No. 5 seed Mihaela Buzarnescu and No. 6 seed Aliaksandra Sasnovich both fell, suffering respective 6-1, 6-0 and 3-6, 6-4, 6-4 defeats to Alison Van Uytvanck and Petra Martic.

Elsewhere, Viktoria Kuzmova is through following a 6-2, 6-4 defeat of Sabine Lisicki.