Two-time Grand Slam champion Garbine Muguruza needed one hour and 17 minutes to earn a 6-3 6-4 victory over fellow Spaniard Carla Suarez Navarro.
Samantha Stosur usually underperforms in her home country, but this time she came back from a set down to record a confidence-boosting victory over Dominika Cibulkova 3-6 6-3 6-4. Daria Gavrilova and Ajla Tomljanovic are two Australian representatives that were eliminated from the draw on Monday, falling to Yulia Putintseva and Camila Giorgi, respectively.
The highest seed in action on Monday, seventh seed Kiki Bertens defeated Bernarda Pera 7-5 6-4, while Timea Bacsinszky upset ninth seed Anastasija Sevastova 6-7(3) 6-4 6-4.