Barty - Mertens
Brady - Svitolina
Hsieh - Osaka
Williams - Halep
But yes, the second half of the draw is so strong any of those 8 players could reach the QFs and no one would blink an eye and say or think it's unwarranted. Really anything could happen there. Hsieh would have to peak to move past Marketa, having watched Marketa's third round match, she wasn't exactly kryptonite and Cirstea rather beat herself, Hsieh isn't the kind of player to self implode like that... rather the opposite, she gets the opponent to do so. And a Hsieh - Osaka QF has the potential to be legendary given their past encounter but then again Muguruza isn't exactly a scrub either and Naomi will have to work a lot for her place in the next round. Sabalenka - Williams and Halep - Swiatek are absolutely unpredictable. I have no idea how these matches will go. I chose Williams against Sabalenka based rather on their peaks and Halep because she is my fave ddd.
Svitolina does have a decent path to semis but Pegula will not bow out easily and then she could meet Brady in the quarterfinals, Brady has been long overdue a slam breakthrough so I don't see why she wouldn't finally have it here. Barty - Mertens is the easiest QF to predict on paper but Muchova could be tricky for Elise and a peaking Rogers could also get the job done against Ash.
Ugh this draw is exciting!
Edit: Brady did have her slam breakthrough at the US Open but alas, I forgot about it.