The 19-year-old American, Learner Tien, knocked out Daniil Medvedev in an instant classic, while Iga Swiatek, Emma Raducanu and Jannik Sinner also won

Early danger signs for 18th seed Hubert Hurkacz who is serving to stay in the first set against Miomir Kecmanovic at 3-5 and now down 0-30. The Pole reached the quarter-finals at Melbourne Park last year but is quickly in a spot of bother on John Cain Arena today.

Amanda Anisimova is the first to hold serve as a pair of powerful forehand winners are too much for Emma Raducanu. The American leads 2-1.