Eastbourne - Defending champion Caroline Wozniacki started her grass-court season brightly, while top remaining seed Karolina Pliskova moved into round three at Eastbourne on Monday.
Newly crowned world number one Ashleigh Barty withdrew from the Wimbledon tune-up due to an arm injury after her efforts in winning the Birmingham Classic on Sunday.
That means world number three Pliskova is the highest-ranked player in the draw and she became the first player into the last 16 with a 6-3, 6-3 win over Russia's Margarita Gasparyan.
Wozniacki, seeded 11th, was also a comfortable winner in the first round as the Dane dispatched Kirsten Flipkens 6-3, 6-4.
"I love playing here, it brings back great memories for me," said Wozniacki, who also won at Eastbourne in 2009.
"I was here for the first time when I was 14, so that's basically half of my life."
Wozniacki faces German Andrea Petkovic in round two.
Eastbourne WTA/ATP results on Monday (x denotes seeding):
Taylor Fritz (USA) bt Paul Jubb (USA) 6-2, 6-3
Steve Johnson (USA) bt Reilly Opelka (USA) 7-6 (7/4), 6-3
Hubert Hurkacz (POL) bt Marco Cecchinato (ITA x7) 6-4, 6-4
Fernando Verdasco (ESP x5) bt John Millman (AUS) 6-7 (3/7), 6-4, 6-1
Sam Querrey (USA) bt Mikhail Kukushkin (KAZ) 6-3, 7-6 (7/4)
Karolina Pliskova (CZE x2) bt Margarita Gasparyan (RUS) 6-3, 6-3
Ons Jabeur (TUN) bt Evgeniya Rodina (RUS) 1-6, 7-6 (7/3), 7-5
Daria Gavrilova (AUS) bt Viktorija Golubic (SUI) 6-0, 6-7 (2/7), 7-6 (8/6)
Hsieh Su-Wei (TPE) bt Camila Giorgi (ITA) 6-3, 4-6, 6-4
Tamara Zidansek (SLO) bt Carla Suarez Navarro (ESP) 4-6, 7-5, 7-5
Caroline Wozniacki (DEN x11) bt Kirsten Flipkens (BEL) 6-3, 6-4
Yulia Putintseva (KAZ) bt Danielle Collins (USA) 5-0 -- retired
Jelena Ostapenko (LAT) bt Mihaela Buzarnescu (ROU) 6-4, 6-4
Marketa Vondrousova (CZE x13) bt Zheng Saisai (CHN) 6-2, 6-3