This can be a pretty fast one for Iga as I don't see how Zheng can present a threat today. In normal conditions, she could maybe put up a fight, but considering she is coming to this clash after 2 difficult matches (6+ hours in the last 2 days) I can't give her much chances. She deserved to be knocked out vs Navarro if I'm going to be honest and was really bad under pressure vs Kerber (0-5 saved break chances). On top of that bas 0-6 vs Iga in direct H2H with Iga winning both '24 encounters pretty comfortable (Zheng won 5 games in each match).
After that lost set vs Collins, Iga will demonstrate the raw power again and should advance here easily (key word - SHOULD).
I started my Betrush journey with the same tip on Iga (vs Paolini) and I hope for the same outcome get again.