Kazakhstan are on the verge of sending last year's Davis Cup champions Argentina out of the top-tier World Group after winning Saturday's doubles rubber.
Timur Khabibulin and Alexander Nedovesov recovered from dropping the first set to beat Argentina's Maximo Gonzalez and Andres Molteni 5-7 6-4 7-5 6-4.
That gives Kazakhstan a 2-1 lead in the best-of-five tie.
Sunday's first reverse singles pits together each team's top-ranked player, with Mikhail Kukushkin of Kazakhstan playing Argentina's Diego Schwartzman.
Dmitry Popko will play Guido Pella in the final rubber.
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Argentina are trying to avoid dropping out of the World Group for the first time since 2001.
Kazakhstan are bidding for an immediate return to the top level after relegation last year.
