Serena Williams of the United States prepares to return serve in her first round match against Belinda Bencic of Switzerland on day two of the 2017 Australian Open at Melbourne Park on January 17, 2017 in Melbourne, Australia. Serena Williams launched her bid for a 23rd grand slam title with a 6-4 6-3 win over Belinda Bencic at the Australian Open on Tuesday, swatting aside doubts over her fitness and motivation on a sweltering day at Melbourne Park.