In a confrontation that lasted 4 hours, 59 minutes, Nalbandian and Schwank defeated Marin Cilic and Ivo Karlovic 3-6, 7-6 (8-6), 6-3, 6-7 (6-8), 8-6.
The competitors played 355 points in the match, the results of which put the Argentines on the brink of moving to the semifinals against either Serbia or the Czech Republic.
In Sunday's reverse singles, Juan Martin Del Potro will attempt to clinch a victory when he meets Cilic in the opening match. Nalbandian is scheduled to take on Karlovic in the second contest.
The Czech Republic holds a 2-1 lead over Serbia in its quarterfinal duel.
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