The Finn pushed the number two seed all the way in a competitive first set before Nadals class eventually told and he came through 7-5 6-3 6-1.
Nieminen had two set points at 15-40 on Nadals serve when 5-4 up in the opening set but could not convert either. Nadal then took the upper hand in the 11th game when he broke the Finn before comfortably holding his serve.The Spaniard broke the 24th seed early in the second and followed that up with another break to move into a commanding 4-1 lead.
Nieminen broke back when Nadal sent a backhand into the net and then held his serve to claw his way back to 4-3.
But Nadal again stamped his superiority on proceedings to take the next two games and enjoy a commanding two sets to love lead.
The Spaniard then broke Nieminen again in the second game of the third set when his opponent could only volley Nadals low sliced return into the net.
And he never looked back from then on as he eased through to the semi-finals of the seasons opening Grand Slam.