The Spaniard dominated the match from the onset, breaking twice in the opening set to take an early lead.
He broke again in the second, leaving him with a comfortable two sets to love lead with Lacko finding the 25-year-old difficult to contain.
Nadal continued his imperious form in the third set, displaying the sort of form that took him to the number one spot in the world. He broke Lacko once more late in the tie and served for a spot in the fourth round.
Nadal last triumphed in the Australian Open in 2009.