I think I'm going to bet 3 sets for Azerenka v Errani.
Errani is at home so I'd expect her to not lose in straight sets, Azarenka can be unpredictable and I'm not even sure if she'll win so I'm putting this down to 3 sets.
Worth noting that Azarenka has never dropped a set v Errani (at least in the last 4 years) but I think Errani will be fresh considering she didn't play yesterday and Azarenka struggled.