Top seeds Juan Monaco and Juan Ignacio Chela were both winners on Friday and advanced to the semifinals at the VTR Open tennis event.

Monaco, the No. 1 seed from Argentina, overcame a first-set loss to Albert Montanes, the tournament's fifth seed, to take a 3-6, 6-1, 6-1 victory.

Monaco had never beaten the Spaniard in two prior meetings and it looked like he would fall again, but used a dominating final two sets to take the win and will now try to reach his third finals at this event.

He also reached the title contest of this clay-court event in 2010 at Santiago, and 2008.

Chela, the second seed, outlasted Brazil's Joao Souza 5-7, 7-6 (8-6), 6-1 in a match that lasted three hours. The Argentinean staved off 10-of-13 break chances by Souza and converted on 4-of-8 of his own, including three in the third set, en route to the semis.

In other quarterfinal action, seventh-seeded Carlos Berlocq grounded qualifier and fellow Argentine Federico Delbonis 6-3, 6-4, and Frenchman Jeremy Chardy downed Portugal's Frederico Gil 6-2, 7-6 (7-5).

Monaco will face off against Chardy in the semis, while Chela will do battle with Berlocq.

The 2012 Vina del Mar champion will collect $71,900.