Top-ranked Ash Barty and defending champion Naomi Osaka play their second-round matches as they head toward a possible meeting in the fourth round at Melbourne Park.

Rafael Nadal, seeking a record 21st Grand Slam singles title, also is in action. Nadal is tied with Novak Djokovic and Roger Federer on 20 for the most by a man in tennis history. Third-seeded Alexander Zverev plays Australian John Millman in a night match.

WEDNESDAY FORECAST

Sunny, high of 27 Celsius (81 Fahrenheit).

TUESDAY’S WEATHER

Mostly sunny, high of 21 C (70 F)

TUESDAY’S KEY RESULTS

Women’s First Round: No. 2 Aryna Sabalenka beat Storm Sanders 5-7, 6-3, 6-2; No. 3 Garbine Muguruza beat Clara Burel 6-3, 6-4; No. 6 Anett Kontaveit beat Katerina Siniakova 6-2, 6-3; No. 7 Iga Swiatek beat Harriet Dart 6-3, 6-0; No. 10 Anastasia Pavlyuchenkova beat Anna Bondar, 6-2, 6-1; No. 12 Elena Rybakina beat Zarina Diyas 6-7 (3), 7-6 (3), 6-1; No. 14 Simona Halep beat Magdalena Frech 6-4, 6-3; No. 17 Emma Raducanu beat Sloane Stephens 6-0, 2-6, 6-1; No. 19 Elise Mertens beat Vera Zvonareva 6-4, 7-5; Sorana Cirstea beat No. 20 Petra Kvitova 6-2, 6-2; Maddison Inglis beat No. 23 Leylah Fernandez 6-4, 6-2.

Men’s First Round: No. 2 Daniil Medvedev beat Henri Laaksonen 6-1, 6-4, 7-6 (3); No. 4 Stefanos Tsitsipas beat Mikael Ymer 6-2, 6-4, 6-3; No. 5 Andrey Rublev beat Gianluca Mager 6-3, 6-2, 6-2; No. 9 Felix Auger-Aliassime beat Emil Ruusuvuori 6-4, 0-6, 3-6, 6-3, 6-4; No. 11 Jannik Sinner beat Joao Sousa 6-4, 7-5, 6-1; No. 13 Diego Schwartzman beat Filip Krajinovic 6-3, 6-4, 7-5; No. 15 Roberto Bautista Agut beat Stefano Travaglia 7-6 (2), 6-4, 5-7, 6-1; Maxime Cressy beat No, 22 John Isner 7-6 (2), 7-5, 6-7 (4), 6-7 (4), 6-4; Andy Murray beat No. 21 Nikoloz Basilashvili 6-1, 3-6, 6-4, 6-7 (5), 6-4; No. 24 Daniel Evans beat David Goffin 6-4, 6-3, 6-0; Nick Kyrgios beat Liam Broady 6-4, 6-4, 6-3.

STAT OF THE DAY

49 — Andy Murray’s career tally of wins in Australian Open singles matches, the most by any man at a Grand Slam tournament without winning the title. Murray, a five-time runner-up at the Australian Open, won his 48th match here in 2017.

QUOTE OF THE DAY

“You are so nervous when everybody can beat everyone, so very happy I managed to finish it off” — No. 3-seeded Garbiñe Muguruza on her perfect 10-year streak in first-round matches at the Australian Open.