BUENOS AIRES, Argentina (AP) -- Top-seeded Rafael Nadal beat local qualifier Facundo Arguello 6-4, 6-0 on Wednesday to reach the quarterfinals of the Argentina Open.

Nadal has yet to reach a final in three tournaments this season and was beaten in the semifinals last week in Rio de Janeiro, ending his 52-match unbeaten run on clay.

He has had illness and injury problems the last few seasons, and this year he says he's fit but not yet match conditioned.

In other key matches, third-seeded Pablo Cuevas of Uruguay advanced with a 7-6 (4), 6-1 win against Guido Andreozzi of Argentina, but No. 5 Leonardo Mayer was ousted by fellow Argentine Juan Monaco 6-4, 6-4.