Giraldo lost to Spaniard Tommy Robredo in the 2011 championship match of the Chile event, but this time made an early exit, bowing to Argentina's Leonardo Mayer 7-6 (7-5), 6-1 at Club Naval de Campo Las Salinas.
Eighth-seeded Italian Filippo Volandri also fell victim to an upset Monday, going down to Brazil's Joao Souza 1-6, 7-5, 7-6 (7-5).
In the opening day's final match, Russia's Igor Andreev beat Paul Capdeville of Chile 3-6, 6-3, 6-4.
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