Tennis legends Roger Federer and Serena Williams will play against each other for the first time.
They will meet on court at the Hopman Cup on Tuesday 1 January when Switzerland face the USA in Perth.
They will play in men's and women's singles rubbers before meeting in the mixed doubles alongside partners Belinda Bencic and Frances Tiafoe.
Federer and Williams, both 37, have won a combined 43 Grand Slam titles.