Sixth seed Karolina Pliskova progressed to the Australian Open second round with a straight-set victory over Paraguay's Veronica Cepede Royg.
Former world number one Pliskova, who reached the quarter-finals last year, won 6-3 6-4 on Rod Laver Arena.
Angelique Kerber, the 2016 champion, made it 10 singles wins in a row this year by seeing off fellow German Anna-Lena Friedsam 6-0 6-4.
French eighth seed Carolina Garcia beat Germany's Carina Witthoeft 7-5 6-3.
She will face Czech Marketa Vondrousova in round two on Thursday.
(BBC)