The British Number 4 Katie Boulter who was born in August 1, 1996 had been trailing 6-3 to Bondar when she withdrew after suffering what appeared to be an injury to her left leg.
It brought a halt to an impressive run of form that had seen her reel off eight straight wins, including victory over Anna Blinkova in the final in Grenoble to end her four-year wait for a WTA singles title.
Elsewhere second-seeded Sorana Cirstea progressed with a 6-3 7-5 win over Stefanie Voegele of Switzerland to set up a quarter-final meeting with Bondar.
No 3 seed Viktorija Golubic meanwhile overcame Mai Hontama of Japan 1-6 6-4 6-4 and is now due to face Russia’s Vitalia Diatchenk, who beat Anna-Lena Friedsam of Germany 6-3 2-6 6-4.
Alison Van Uytvanck joins them in the next round after her 6-2 6-4 win over Russia’s Varvara Gracheva.
Britain’s Heather Watson is in action in the Monterrey Open on Thursday when she takes on Spanish eighth seed Nuria Parrizas Diaz.
