The 26-year-old needed 71 minutes to win in straight sets, 6–3, 6–2.
But it was not a smooth journey to advance in the tournament in Melbourne.
Top-seeded Aryna Sabalenka started shakily but eventually got her game in order and controlled the match on Rod Laver Arena.
It's always tough matches against her, she says.
I didn't play my best tennis today and I'm glad I managed to win in two sets.
Sabalenka can become the first woman since Swiss Martina Hingis to win three consecutive titles (1997-1999).
Olympic champion Zheng Qinwen, China, sixth-seeded Norwegian Casper Ruud, and second-seeded Alexander Zverev, Germany, are also through.
Zheng, who lost the final last year, won against 110th-seeded Romanian Anca Todoni.
Ruud advanced after a shaky five-setter against Spanish Jaume Munar, ranked 106th.
It was a really tough match, he says.
Zverev got 6–4, 6–4, 6–4 against Frenchman Lucas Pouille.
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