I have seen it argued that they came close to winning both.
For the former, "Osman Pasha organized a defense and repelled two Russian attacks with colossal casualties on the Russian side. At that point, the sides were almost equal in numbers and the Russian army was very discouraged.[36] Most analysts agree that a counter-attack would have allowed the Ottomans to gain control of, and destroy, the Russians' bridge.[who?] However, Osman Pasha had orders to stay fortified in Plevna, and so he did not leave that fortress."
For the latter, the world was shocked at the Ottoman defeat.
The former hinges on the Ottoman army being competent at this point which sorry but no and the latter,well,it was mostly because the world at large wasn’t aware of the state of the Ottoman army and thought that they could do the bare minimum required by an empire in this period.