The Williams sisters got team jumpers from Big Bash cricketers Muthiah Muralidaran and Aaron Finch.
It was the World No.1 and former World No.1's reward for playing cricket on a hotel rooftop.
Li Na and Maria Sharapova held autograph sessions at the Crown Casino before the tournament began.
And that wasn't the only media appearance Sharapova made before getting down to the on-court business.
The Career Grand Slam holder also appeared at the Woman With Drive event at Porsche Centre Melbourne.
She played mini-tennis with the guests and answered fan questions on stage during the event.
Another one of the WTA's marquee names - Victoria Azarenka - took part in the draw ceremony on Friday.
Alongside fellow defending champion Novak Djokovic, Azarenka headed into the city with her trophy.
Azarenka has won the last two Australian Opens; Djokovic has won the last three and four overall.
Rod Laver Arena was packed on Saturday for a very special event...
It was Kids Day at the Australian Open, and Australian No.1 Sam Stosur met Dora the Explorer.
Roger Federer, who has been experimenting with different sized racquets, did it to the extreme.
Eugenie Bouchard joined Stosur, Azarenka, a slew of ATP World Tour stars and characters on court.
Elsewhere on Kids Day, SpongeBob SquarePants and Patrick Star joined Alicia Molik and friends.
Chinese rising stars Wu Di, Duan Ying-Ying, Zhang Ze and Tang Hao Chen posed with the Chinese flag.