If you think a guy with such a crap BH can beat Nadal on clay you are beyond delusional.
Look at Nadal's losses people. Even this year that he's struggling he only lost to guys with great BHs, who can take his shots early and redirect it also if needed.
The lone exception being Wawrinka, who can stay far behind the baseline and still achieve a powerful shot on his left side and even tho he always had a great BH, for not being able to play closer to the baseline with consistency to take time away from Nadal he was like 0-15 against the Spaniard.
Getting returns from Dimugtrov is not the same as getting them from Nadal. Also, he had a monster day yesterday, hitting everything he put his mind to. To beat Nadal, he'd had to take it up a notch - if that's even possible with Sock.