Second-seeded Nicolas Almagro was round winner Thursday, while third-seeded Gilles Simon was upset at the Copa Claro tennis event.

Almagro handled Argentine Federico Delbonis 6-3, 6-2 in 73 minutes on the red clay at Buenos Aires Lawn Tennis Club.

Almagro of Spain topped Argentine Juan Ignacio Chela in last year's Buenos Aires finale and is fresh off his title in Sao Paulo last week.

Argentine crowd favorite Carlos Berlocq blew away the French Simon 6-2, 6-1 in 66 minutes.

David Nalbandian took down fifth-seeded Juan Monaco 6-3, 6-1 in a battle of Argentine players. Nalbandian will face Berlocq in the quarterfinals.

The former Wimbledon runner-up Nalbandian titled here in 2008, while Monaco was the Buenos Aires winner in 2007 and runner-up in 2009.

Meanwhile, qualifier Igor Andreev posted an upset by dousing seventh-seeded Spaniard Fernando Verdasco 7-6 (7-3), 6-3. The tight match featured only three breaks of serve, including two for the winner from Russia.

Andreev will do battle with Almagro in the quarters.

The 2012 Buenos Aires champion will earn $82,900.