MELBOURNE, Jan 16 (Reuters) - Order of play on the main showcourts on the first day of the Australian Open on Monday (play begins at 0000 GMT, prefix number denotes seeding): ROD LAVER ARENA Tatjana Maria (Germany) v 5-Maria Sakkari (Greece) Camila Osorio (Colombia) v 13-Naomi Osaka (Japan) Not before 0300 GMT Marcos Giron (U.S.) v 6-Rafa Nadal (Spain) From 0800 GMT 1-Ash Barty (Australia) v Lesia Tsurenko (Ukraine) 3-Alexander Zverev (Germany) v Daniel Altmaier (Germany) MARGARET COURT ARENA Fiona Ferro (France) v 15-Elina Svitolina (Ukraine) Brandon Nakashima (U.S.) v 7-Matteo Berrettini (Italy) Wang Qiang (China) v 18-Coco Gauff (U.S.) From 0800 GMT Feliciano Lopez (Spain) v John Millman (Australia) Ajla Tomljanovic (Australia) v 8-Paula Badosa (Spain) JOHN CAIN ARENA Laslo Djere (Serbia) v 14-Denis Shapovalov (Canada) 10-Hubert Hurkacz (Poland) v Egor Gerasimov (Belarus) Not before 0600 GMT 11-Sofia Kenin (U.S.) v Madison Keys (U.S.) Jaume Munar (Spain) v 18-Aslan Karatsev (Russia)