Top seed Anna Kalinskaya of Russia had to battle in the second set before eliminating Switzerland’s Simona Waltert 6-2, 7-6 (3) on Wednesday in the Round of 16 at the Singapore Tennis Open.

Kalinskaya, ranked No. 18 in the world, converted 3 of 5 break-point opportunities and saved 4 of 5. Waltert, ranked 179th, had more aces (6-0) and more double faults (5-0).

Sixth-seed Camila Osorio of Colombia rallied from dropping the first set to defeat the Czech Republic’s Dominika Salkova 3-6, 6-2, 6-4. American An Li ousted Russia’s Maria Timofeeva in straight sets, as did Thailand’s Mananchaya Swangkaew over Spain’s Cristina Bucsa.

Upper Austria Ladies Linz

Third seed Maria Sakkari of Greece saved the only break point she faced in defeating Bulgaria’s Viktoriya Tomova 6-3, 6-2 in 77 minutes in the Round of 16 in Linz, Austria.

Sakkari, ranked No. 31 in the world, won 74.4 percent (29 of 39) of first-serve points, compared to 55 percent (22 of 40) for Tomova. Sakkari converted 3 of 7 break-point opportunities.

Other seeds winning in straight sets were No. 6 Anastasia Potapova of Russia, No. 7 Elina Avanesyan of Armenia and No. 8 Clara Tauson of Denmark. Russia’s Anna Blinkova ousted Austria’s Sinja Kraus 7-6 (3), 6-2 in one hour, 39 minutes in a clash of unseeded players.

–Field Level Media