Amanda Anisimova will next face Naomi Osaka after downing Belinda Bencic ©Getty Images

Amanda Anisimova of the United States stunned Swiss Olympic gold medallist Belinda Bencic to set up a meeting with Japanese defending champion Naomi Osaka at the Australian Open in Melbourne.

Bencic, seeded 22nd, came unstuck against Anisimova who tallied 28 winners and seven cases in an impressive 6-2, 7-5 triumph.

Anisimova now faces a third-round clash with Osaka who overpowered American Madison Brengle in a 6-0, 6-4 success.

World number one and home favourite Ashleigh Barty lost just two games in her opening-round match against Lesia Tsurenko and was equally dominant against Italy’s Lucia Bronzetti.

Barty took just 52 minutes to down Bronzetti 6-1, 6-1 and will next tackle Italian Camila Giorgi who battled past Czech player Tereza Martincová 6-2, 7-6.

Madison Keys, who dispatched fellow American Sofia Kenin in the first round, continued her fine form as she defeated Jaqueline Cristian of Romania 6-2, 7-5.

There were also impressive wins for French Open champion Barbora Krejčíková of the Czech Republic and Greece’s Maria Sakkari who beat Chinese players Wang Qiang and Zheng Qinwin in straight sets.

Ukrainian 15th seed Elina Svitolina had to battle hard before Frenchwoman Harmony Tan retired hurt when 6-3, 5-7, 5-1 down.

Two-time Australian Open champion Victoria Azarenka will take on Svitolina in the third round after the Belarusian saw off Jil Teichmann 6-1, 6-2.

In the men’s draw, Spain’s Rafael Nadal continued his quest for a record 21st Grand Slam title with a 6-2, 6-3, 6-4 demolition of German qualifier Jannick Hanfmann.

Rafael Nadal produced another ruthless showing to reach the third round in Melbourne ©Getty Images
Rafael Nadal produced another ruthless showing to reach the third round in Melbourne ©Getty Images

"As I said before the tournament, things are not going to be perfect, but every day that I spend on court, the chances to play better are higher," said Nadal.

"Things that I can improve I have to improve.

"Winning today allows me to practice again tomorrow, to be ready for another match.

"After two matches it's the moment to make a step forward."

Germany’s Olympic champion and third seed Alexander Zverev was in no mood to spend too much time on court as he thumped Australia’s John Millman 6-4. 6-4, 6-0.

Tenth seed Hubert Hurkacz of Poland bowed out after coming up against inspired Frenchman Adrian Mannarino who powered to a 6-4, 6-2, 6-3 victory.

Italian Matteo Berrettini, seeded seventh, dropped another set but emerged victorious, beating Stefan Kozlov of the US 6-1, 4-6, 6-4, 6-1.

Canadian 14th seed Denis Shapovalov came through a five-set battle, defeating Kwon Soon-woo of South Korea 7-6, 6-7, 6-7, 7-5, 6-2.

Competition continues tomorrow with more second-round matches.