We need to discount Zhang's win in China (as there may be a home court factor and crowd support advantage). But, Konta won in a neutral venue.
At any rate, this is a great opportunity for both players (both are unseeded) to make SF. So, neither will go out easily. So, while I am not so sure of winner, I am sure that it will go to three sets.
Konta has more experience than Zhang. After all Zhang has not won a single GS match before this AO. Besides, the coaching and fitness regimen is below standard for Asian players (not player's fault, the economy's fault). So, I am leaning with Konta in 3.