No. 3 seed Bernarda Pera survived a three-set opening match and defeated Zeynep Sonmez of Turkey 6-2, 1-6, 6-4 in the first round of the Hamburg European Open on Monday in Germany.
Pera had a 4-0 edge in aces and saved seven of 10 break points to get past Sonmez.
Austrian fifth seed Julia Grabher had an easier time in beating Romania's Miriam Bulgaru 6-4, 6-4. No. 6 seed Yulia Putintseva of Kazakhstan and No. 8 seed Camila Osorio of Colombia also won in straight sets.
German 19-year-old Noma Noha Akugue won her WTA main-draw debut, beating Brazil's Laura Pigossi 7-5, 6-4. Germany's Jule Niemeier, Argentina's Nadia Podoroska, Kaia Kanepi of Estonia and Diana Shnaider of Russia also advanced.
Ladies Open Lausanne
No. 6 seed Mirra Andreeva of Russia cruised past Ukraine's Dayana Yastremska 6-0, 6-2 in first-round action in Switzerland.
Andreeva won all seven of her return games, going 7-for-10 in converting break-point opportunities.
No. 8 seed Elina Avanesyan of Russia also advanced. She led 6-2, 2-0 when countrywoman Evgeniya Rodina retired.
Other winners included Switzerland's Jil Teichmann, Argentina's Julia Riera and Anna Bondar of Hungary.
BNP Paribas Warsaw Open
Slovakia's Viktoria Hruncakova fired 16 aces but needed two hours and two minutes to dispatch countrywoman Kristina Kucova 7-5, 6-3 in the first round in Poland.
Germans Laura Siegemund and Yanina Wickmayer also won their opening matches. Siegemund defeated Poland's Maja Chwalinska 6-4, 6-1, and Wickmayer beat Japan's Nao Hibino 6-2, 6-4.
World No. 1 Iga Swiatek of Poland is the top seed in her home country's open. She will play her first match Tuesday against Nigina Abduraimova of Uzbekistan.
--Field Level Media