Nadal broke Stepanek twice in each set and the Czech couldn’t find any response to the Spaniard’s ruthless shot making.
In the last 16, the world no.2 will play Kei Nishikori of Japan, who defeated Lukas Rosol of Czech Republic 6-4 6-2.
German Florian Mayer surprisingly beat no.10 seed John Isner in just an hour and seven minutes 6-4 6-2.
Isner saved break points in the 6th game, but Mayer eventually broke him in the 9th game and sealed the first set with his own serve.
Mayer was on the roll in set 2 and he took Isner’s serve twice to cruise to a big win.