Juan Martin del Potro expressed his confidence on Tuesday that Argentina could "strike a blow" against the Rafael Nadal-inspired Spanish when the two sides meet in the Davis Cup finals in December.
Del Potro, ranked 13th, won both his singles rubbers to help Argentina to a 3-2 success over defending champions Serbia on a hardcourt surface in Belgrade at the weekend to set up a showdown with Spain who host the final from December 2-4.
Spain have won all three of their previous meetings with Argentina including the last time the two nations met in the final in Mar del Plata in 2008.
"Now we're heading to brick dust," said del Potro of the tie on clay. "Nadal is the king there and it's going to be very complicated.
"But finals are always different and special, hopefully we'll all arrive in top form and will have four players of a high level to face Spain.
"They (Spain) are the favourites, but if we go in with a low profile and a good attitude this time we'll get a good result. We went to Serbia as well to cause an upset and we struck hard. Hopefully we can repeat this."
Del Potro scored the winning point on Sunday when world number one Novak Djokovic retired injured while trailing the South American 7-6 (7/5), 3-0.
David Nalbandian and Del Potro won the opening day's rubbers although doubles duo Juan Ignacio Chela and Juan Monaco lost their tie. Serb Janko Tipsarevic won the final dead rubber when Monaco retired.
Del Potro added: "The doubles is the point that we're going to have to work most on."
It will be the fourth final for Argentina who have never lifted the title.
Spain have dominated over the last decade, winning in 2000, 2004, 2008 and 2009, and have not lost at home since 1999.