Although Berlocq is playing really well tonight and has been for the most part the last months, Rui is a different player than RRH, and he definitely can beat Charly. He has a good serve, so he should be able to hold better than RRH is doing tonight. He likes being offensive when he has the opportunities. He just needs to get a high percentage of first serves in and be aggressive, return effectively. He can't be passive and allow Berlocq to be the one dictating.
Rui probably would want to play Ciric but if Ciric is hot then it will be tough either way. Ciric is less consistent than Riba so that would give Machado better chances.
Like I say from the begining Rui has very good chances agains Berloq. I'm just saying that will not be easy, but it's like 50-50, to me.
And I don't know Ciric, but with your description of him, I guess that he depends of his serve. And when is serve is on fire, it's very very hard to stop him. But I guess looking at the ranking than his days of "on-fire serve" doesn't happen that many times