“When you have got a weakness of that magnitude, the rest of Zverev’s game is so good, it just shows you how it can hurt you, especially at this level.
“You can’t get away with it. So the big question for Zverev is how is he going to address that problem.”
De Minaur’s win completed a 2-0 victory for the host nation and an ideal start on the opening day of the tournament.
Kyrgios made the perfect start to the day when he beat Jan-Lennard Struff.