The top seed had to survive a tough opening match against Italian Camila Giorgi but destroyed the 90th-ranked Hsieh in exactly one hour in glorious sunshine at Rod Laver Arena.

Hsieh, a two-time grand slam doubles champion, prised three break points but the American saved them all and closed out the match with her seventh ace.

"I think I was really focussed and that first round really helped me because I was really just fighting," world number one Williams told reporters after setting up a third-round clash against 18-year-old Russian Daria Kasatkina.

"I really gave a big effort there. Today again, I just wanted to stay focussed for the whole time.

"I don't think I made that many errors today. Something I was hopefully trying to get back into. And I moved much better today, so slowly but surely, feeling a little bit better."

Williams pulled out of the lead-up Hopman Cup midway through her first match with knee trouble but looked untroubled as she burned around the court to fire 26 winners past the Taiwanese.

She was particularly pleased with her scramble for a winner around the net, which she thought was the first of her career, but poured cold water on the idea of pulling off a between-the-legs trick shot in subsequent matches.

"It's always cool to do something fresh and new," she said.

"I don't do ('tweeners). I'm not good at those. I did when I was younger, and I was terrible at it. I know what I'm good at, and I know things I'm not going to excel at. I'm definitely not going to excel at that shot."

(Editing by John O'Brien)